[Feature]: Emit proposer in submit_proposal event

[dadamu]

Summary

Emit proposer in submit_proposal event

Problem Definition

No response

Proposed Feature

It allows users to track proposal transactions or blocks by event submit_proposal.proposer = "<proposer-address>", and it also allows applications get proposer from transaction event without parsing message or authz message with codec

[akaladarshi]

Hey @julienrbrt, can I work on this?

[akaladarshi]

Hey @julienrbrt, does it require emitting proposer when the voting starts here?.

[julienrbrt]

Hey @julienrbrt, does it require emitting proposer when the voting starts here?.

No, it should be in the event sent in the keeper (and not msg server)