Encoding traits cleanup (#1533)

towards https://github.com/unionlabs/union/issues/1060 (protobuf portion
of that issue)

this pr became massive so i'll do the EthAbi half of
https://github.com/unionlabs/union/issues/1060 in a followup pr.

- update prost codegen to get typeurls generated instead of doing that
all manually (finally)
- kept `unionlabs::TypeUrl`, so as to not have `prost::Name` in our
public api (implemented the former in terms of the latter)
- add attribute macro to generate Encode/Decode implementations by
delegating to a prost generated type (this also does the typeurl
delegation mentioned above)
- add `EncodeAs`/`DecodeAs` convenience traits
- remove `Proto`/`IntoProto`/`TryFromProto`/`FromProto`/etc types and
traits
- remove
`lib/unionlabs/src/ibc/applications/transfer/fungible_token_transfer_data.rs`
as it was unused