Refactor Issuable reply hotkey

app/assets/javascripts/behaviors/markdown/copy_as_gfm.js

...ets/javascripts/behaviors/shortcuts/shortcuts_issuable.js

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

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

...sets/javascripts/notes/components/noteable_discussion.vue

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

...cripts/vue_shared/components/markdown/markdown_editor.vue

spec/frontend/behaviors/copy_as_gfm_spec.js

spec/frontend/behaviors/shortcuts/shortcuts_issuable_spec.js

...end/notes/components/__snapshots__/notes_app_spec.js.snap

spec/frontend/notes/components/comment_form_spec.js

spec/frontend/notes/components/note_form_spec.js

spec/frontend/notes/components/noteable_discussion_spec.js

spec/frontend/notes/components/notes_app_spec.js

...nd/vue_shared/components/markdown/markdown_editor_spec.js