Rename on-chain types

[bddap]

As of version 1.9, polkadot.js does not support type names containing "::". "::" happens to be what we were using as a namespace separator.

Task: Rename, or create aliases for, all on-chain exposed types (types that show up in chain metadata) as discussed in docknetwork/sdk#63. It's the metadata we need to change, so it's ok just to use type aliasing as long as the aliases are used withing substrate macros.

This will require client-side changes; client submodule needs to be updated, src/types.json needs to be updated, as well as some changes to code dealing with construction of on-chain types.