Ppx profiler: Add missing actions and some minor fixes

What

Adds aggregate, span, span_f and stamp actions to the possible ppx actions

Also:

• raises an error when a ppx starts with @profiler but has an unknown action
• fixes some attributes not accepting all possible keys (Key.Apply and Key.Ident were missing in some places)

Why

This should fix !14805 (merged) and make using the ppx profiler easier

How

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