Proto/Events: EMIT types

Context

Two things:

• keep original type (hence annotations) when it is given to EMIT
• no need to give the type to EMIT when we don't care about annotations

Based on !5724 (merged), start at Proto/Events: unparse type earlier

Manually testing the MR

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR