## Description 

This PR allows committee registration command to print unsigned
transaction bytes for offline signing. This is important to validators
who keep their account keys in cold storage.

Also rename `BridgeCommitteeRegistration` to `RegisterBridgeCommittee`
to keep command names consistent


## Test plan 

tested locally.

---

## Release notes

Check each box that your changes affect. If none of the boxes relate to
your changes, release notes aren't required.

For each box you select, include information after the relevant heading
that describes the impact of your changes that a user might notice and
any actions they must take to implement updates.

- [ ] Protocol: 
- [ ] Nodes (Validators and Full nodes): 
- [ ] Indexer: 
- [ ] JSON-RPC: 
- [ ] GraphQL: 
- [ ] CLI: 
- [ ] Rust SDK: