All our actions (both on-wire protobuf and domain types) carry a Action suffix (except for ValidatorUpdate, which is externally defined, and Ics20Withdrawal, to be close to the penumbra code we share).

The Action suffix is redundant because there is no way to confuse the types for items that are not actions, we don't have a consistency among all actions, and we mostly follow Rust naming conventions, which rejects item names that repeats module names (which is the case for us, as we define the domain types in a module called actions).

We should remove the suffix.

┆Issue Number: ENG-907