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/utils/async_client.jsx

@@ -1527,3 +1527,53 @@ export function deleteEmoji(id) {
         }
     );
 }
+
+export function saveReaction(channelId, reaction) {
+    Client.saveReaction(
+        channelId,
+        reaction,
+        null, // the added reaction will be sent over the websocket
+        (err) => {
+            dispatchError(err, 'saveReaction');
+        }
+    );
+}
+
+export function deleteReaction(channelId, reaction) {
+    Client.deleteReaction(
+        channelId,
+        reaction,
+        null, // the removed reaction will be sent over the websocket
+        (err) => {
+            dispatchError(err, 'deleteReaction');
+        }
+    );
+}
+
+export function listReactions(channelId, postId) {
+    const callName = 'deleteEmoji' + postId;
+
+    if (isCallInProgress(callName)) {
+        return;
+    }
+
+    callTracker[callName] = utils.getTimestamp();
+
+    Client.listReactions(
+        channelId,
+        postId,
+        (data) => {
+            callTracker[callName] = 0;
+
+            AppDispatcher.handleServerAction({
+                type: ActionTypes.RECEIVED_REACTIONS,
+                postId,
+                reactions: data
+            });
+        },
+        (err) => {
+            callTracker[callName] = 0;
+            dispatchError(err, 'listReactions');
+        }
+    );
+}