feat: add config and messaging base of contracts

[glihm]

• issue # (WIP of blobstream L3 contract)
• follows contribution guide
• code change includes tests
• breaking change

This PR aims at providing a base impl for appchain core contract on Starknet.

On-going tasks:

• simple base contract (appchain.cairo)
• configuration component
• port messaging
• complete messaging with cancelling
• add first state update with tests without facts registry for messages

We will open issues once this is done for contributions and missing features.

[glihm]

@drspacemn I think we're good for a first PR and review before adding more stuff.

Next PR will be for rust bindings.
And after that we can check the state part. 👍

[drspacemn]

For blobstream_starknet we include unit tests in the module and then the top level tests are for the contract logic itself. An example here would be:

tests/test_appchain.cairo
src/config/tests/test_config.cairo
src/messaging/tests/test_messaging.cairo

Thoughts on that structure?

[glihm]

@drspacemn ready for the second review.
Bumped to 2.5.3, even if OZ has some warnings pending.
Add some testing for appchain update_state function.