Solve cargo-clippy warnings

[marcelstanley]

📚 Context

As of 1.5.1, running cargo clippy -- -A clippy::module_inception from offchain/ results in:

offchain$ cargo clippy -- -A clippy::module_inception
warning: assigning the result of `Clone::clone()` may be inefficient
  --> rollups-events/src/broker/indexer.rs:87:13
   |
87 |             state.inputs_last_id = event.id.clone();
   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `clone_from()`: `state.inputs_last_id.clone_from(&event.id)`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assigning_clones
   = note: `#[warn(clippy::assigning_clones)]` on by default

warning: assigning the result of `Clone::clone()` may be inefficient
  --> rollups-events/src/broker/indexer.rs:99:13
   |
99 |             state.outputs_last_id = event.id.clone();
   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `clone_from()`: `state.outputs_last_id.clone_from(&event.id)`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assigning_clones

warning: `rollups-events` (lib) generated 2 warnings (run `cargo clippy --fix --lib -p rollups-events` to apply 2 suggestions)
warning: item has both inner and outer attributes
 --> /home/marcel/development/cartesi/rollups-node/offchain/target/debug/build/contracts-e6be818570e43ef9/out/input_box.rs:2:1
  |
2 | / #[allow(clippy::too_many_arguments, non_camel_case_types)]
3 | | pub mod input_box {
4 | |     #![allow(clippy::enum_variant_names)]
5 | |     #![allow(dead_code)]
6 | |     #![allow(clippy::type_complexity)]
7 | |     #![allow(unused_imports)]
  | |_____________________________^
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#mixed_attributes_style
  = note: `#[warn(clippy::mixed_attributes_style)]` on by default

warning: item has both inner and outer attributes
 --> /home/marcel/development/cartesi/rollups-node/offchain/target/debug/build/contracts-e6be818570e43ef9/out/authority.rs:2:1
  |
2 | / #[allow(clippy::too_many_arguments, non_camel_case_types)]
3 | | pub mod authority {
4 | |     #![allow(clippy::enum_variant_names)]
5 | |     #![allow(dead_code)]
6 | |     #![allow(clippy::type_complexity)]
7 | |     #![allow(unused_imports)]
  | |_____________________________^
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#mixed_attributes_style

warning: item has both inner and outer attributes
 --> /home/marcel/development/cartesi/rollups-node/offchain/target/debug/build/contracts-e6be818570e43ef9/out/history.rs:2:1
  |
2 | / #[allow(clippy::too_many_arguments, non_camel_case_types)]
3 | | pub mod history {
4 | |     #![allow(clippy::enum_variant_names)]
5 | |     #![allow(dead_code)]
6 | |     #![allow(clippy::type_complexity)]
7 | |     #![allow(unused_imports)]
  | |_____________________________^
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#mixed_attributes_style

warning: item has both inner and outer attributes
 --> /home/marcel/development/cartesi/rollups-node/offchain/target/debug/build/contracts-e6be818570e43ef9/out/cartesi_dapp.rs:2:1
  |
2 | / #[allow(clippy::too_many_arguments, non_camel_case_types)]
3 | | pub mod cartesi_d_app {
4 | |     #![allow(clippy::enum_variant_names)]
5 | |     #![allow(dead_code)]
6 | |     #![allow(clippy::type_complexity)]
7 | |     #![allow(unused_imports)]
  | |_____________________________^
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#mixed_attributes_style

warning: `contracts` (lib) generated 4 warnings
warning: called `map(..).flatten()` on `Option`
   --> types/src/blockchain_config.rs:128:18
    |
128 |                   .map(|c| c.address)
    |  __________________^
129 | |                 .flatten());
    | |__________________________^ help: try replacing `map` with `and_then` and remove the `.flatten()`: `and_then(|c| c.address)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_flatten
    = note: `#[warn(clippy::map_flatten)]` on by default

warning: called `map(..).flatten()` on `Option`
   --> types/src/blockchain_config.rs:133:18
    |
133 |                   .map(|c| c.address)
    |  __________________^
134 | |                 .flatten());
    | |__________________________^ help: try replacing `map` with `and_then` and remove the `.flatten()`: `and_then(|c| c.address)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_flatten

warning: called `map(..).flatten()` on `Option`
   --> types/src/blockchain_config.rs:138:18
    |
138 |                   .map(|c| c.address)
    |  __________________^
139 | |                 .flatten());
    | |__________________________^ help: try replacing `map` with `and_then` and remove the `.flatten()`: `and_then(|c| c.address)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_flatten

warning: `types` (lib) generated 3 warnings (run `cargo clippy --fix --lib -p types` to apply 3 suggestions)
warning: in a `match` scrutinee, avoid complex blocks or closures with blocks; instead, move the block or closure higher and bind it with a `let`
  --> graphql-server/src/http.rs:67:17
   |
67 |           move || {
   |  _________________^
68 | |             let res =
69 | |                 query.execute_sync(&http_context.schema, &http_context.context);
70 | |             serde_json::to_string(&res)
71 | |         },
   | |_________^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#blocks_in_conditions
   = note: `#[warn(clippy::blocks_in_conditions)]` on by default

warning: `graphql-server` (lib) generated 1 warning
warning: called `map(f)` on an `Option` value where `f` is a closure that returns the unit type `()`
  --> dispatcher/src/drivers/context.rs:81:9
   |
81 | //         self.last_finished_epoch.map(|last_finished_epoch| {
82 | ||             // Asserting that the calculated epoch comes after the last finished epoch.
83 | ||             // (If last_finished_epoch == None then we don't need the assertion.)
84 | ||             assert!(input_epoch > last_finished_epoch)
85 | ||         });
   | ||__________^- help: try: `if let Some(last_finished_epoch) = self.last_finished_epoch { ... }`
   |  |__________|
   |
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#option_map_unit_fn
   = note: `#[warn(clippy::option_map_unit_fn)]` on by default

warning: `dispatcher` (lib) generated 1 warning
warning: called `map(..).flatten()` on `Option`
   --> authority-claimer/src/checker.rs:126:14
    |
126 |               .map(|claims| claims.last()) // Maps to Option<Option<Claim>>
    |  ______________^
127 | |             .flatten() // Back to only one Option
    | |______________________^ help: try replacing `map` with `and_then` and remove the `.flatten()`: `and_then(|claims| claims.last())`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_flatten
    = note: `#[warn(clippy::map_flatten)]` on by default

warning: called `map(..).flatten()` on `Option`
  --> authority-claimer/src/config/contracts.rs:56:18
   |
56 |                   .map(|c| c.address)
   |  __________________^
57 | |                 .flatten());
   | |__________________________^ help: try replacing `map` with `and_then` and remove the `.flatten()`: `and_then(|c| c.address)`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_flatten

warning: called `map(..).flatten()` on `Option`
  --> authority-claimer/src/config/contracts.rs:61:18
   |
61 |                   .map(|c| c.address)
   |  __________________^
62 | |                 .flatten());
   | |__________________________^ help: try replacing `map` with `and_then` and remove the `.flatten()`: `and_then(|c| c.address)`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_flatten

warning: bound is defined in more than one place
  --> state-server/src/lib.rs:29:25
   |
29 | pub async fn run_server<F: Foldable<UserData = Mutex<UserData>> + 'static>(
   |                         ^
...
34 |     F: serde::ser::Serialize,
   |     ^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#multiple_bound_locations
   = note: `#[warn(clippy::multiple_bound_locations)]` on by default

warning: `authority-claimer` (lib) generated 3 warnings (run `cargo clippy --fix --lib -p authority-claimer` to apply 3 suggestions)
warning: `state-server` (lib) generated 1 warning
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.29s

✔️ Solution

Change code to remove warnings.

📈 Subtasks

• Apply suggestions made by clippy
• Address remaining warnings
• Make sure everything works as expected