Investigate the use of DomainType blanket implementation

[adizere]

Looking at this now and wondering why we need impl DomainType<RawMyType> for <MyType> for many of these. Just the TryFrom/From would be enough. The code compiles and runs fine if we remove all except the cases where RawMyType is not a prost message but wire bytes. For example the client state that is stuffed into an Any type as Vec, or merkle proofs.

(Note - the question is general not only for this PR. We have this pattern everywhere in the code)

Originally posted by @ancazamfir in informalsystems/ibc-rs#391 (comment)