Hide user attributes behind a feature flag

app/assets/javascripts/notes/components/note_header.vue

app/controllers/projects/incidents_controller.rb

app/controllers/projects/issues_controller.rb

app/controllers/projects/merge_requests_controller.rb

config/feature_flags/development/remove_user_attributes.yml

ee/app/controllers/groups/epics_controller.rb

ee/spec/features/discussion_comments/epic_spec.rb

..._reports/components/__snapshots__/event_item_spec.js.snap

...vue_shared/security_reports/components/event_item_spec.js

...tend/vue_shared/security_reports/components/modal_spec.js

...ctions/issue/status_page_quick_actions_shared_examples.rb

spec/features/discussion_comments/issue_spec.rb

spec/features/discussion_comments/merge_request_spec.rb

spec/features/issuables/markdown_references/jira_spec.rb

spec/features/issues/resource_label_events_spec.rb

spec/features/merge_request/user_comments_on_diff_spec.rb

...ures/merge_request/user_comments_on_merge_request_spec.rb

...e_request/user_views_user_status_on_merge_request_spec.rb

spec/features/profiles/user_edit_profile_spec.rb

spec/frontend/notes/components/note_header_spec.js