Report abuse from a users comment in Epics

Release notes

Users can now report comments in epics as abusive by following these steps.

Summary

Comments within an Epic have an actions dropdown which has options; Copy link and Delete comment (if user has relevant permissions for the group), but the option to report a comment for abuse is missing, which is present for comments within an Issue.

Report abuse action for comments depends on reportAbusePath which is exposed on note_entity via app/serializers/note_entity.rb#L69, but its equivalent EE serializer doesn't have it.

Proposal

We need to update ee/app/serializers/ee/note_entity.rb to expose report_abuse_path to make the Epic comments show Report abuse action.

Designs

See design mock-up in: #389992 (comment 1265606473)