PLT-1378 Initial version of emoji reactions (#4520)

* Refactored emoji.json to support multiple aliases and emoji categories

* Added custom category to emoji.jsx and stabilized all fields

* Removed conflicting aliases for :mattermost: and :ca:

* fixup after store changes

* Added emoji reactions

* Removed reactions for an emoji when that emoji is deleted

* Fixed incorrect test case

* Renamed ReactionList to ReactionListView

* Fixed 👍 and 👎 not showing up as possible reactions

* Removed text emoticons from emoji reaction autocomplete

* Changed emoji reactions to be sorted by the order that they were first created

* Set a maximum number of listeners for the ReactionStore

* Removed unused code from Textbox component

* Fixed reaction permissions

* Changed error code when trying to modify reactions for another user

* Fixed merge conflicts

* Properly applied theme colours to reactions

* Fixed ESLint and gofmt errors

* Fixed ReactionListContainer to properly update when its post prop changes

* Removed unnecessary escape characters from reaction regexes

* Shared reaction message pattern between CreatePost and CreateComment

* Removed an unnecessary select query when saving a reaction

* Changed reactions route to be under /reactions

* Fixed copyright dates on newly added files

* Removed debug code that prevented all unit tests from being ran

* Cleaned up unnecessary code for reactions

* Renamed ReactionStore.List to ReactionStore.GetForPost

webapp/components/rhs_comment.jsx

@@ -6,6 +6,7 @@ import FileAttachmentListContainer from './file_attachment_list_container.jsx';
 import PendingPostOptions from 'components/post_view/components/pending_post_options.jsx';
 import PostMessageContainer from 'components/post_view/components/post_message_container.jsx';
 import ProfilePicture from 'components/profile_picture.jsx';
+import ReactionListContainer from 'components/post_view/components/reaction_list_container.jsx';
 import RhsDropdown from 'components/rhs_dropdown.jsx';
 
 import TeamStore from 'stores/team_store.jsx';
@@ -404,6 +405,10 @@ export default class RhsComment extends React.Component {
                                 {message}
                             </div>
                             {fileAttachment}
+                            <ReactionListContainer
+                                post={post}
+                                currentUserId={this.props.currentUser.id}
+                            />
                         </div>
                     </div>
                 </div>