Enable client-side aggregations for reactions

If reactions are enabled, we need to enable client-side aggregation in the
`MatrixClient` to access the data.

src/MatrixClientPeg.js

@@ -175,6 +175,8 @@ class MatrixClientPeg {
     }
 
     _createClient(creds: MatrixClientCreds) {
+        const aggregateRelations = SettingsStore.isFeatureEnabled("feature_reactions");
+
         const opts = {
             baseUrl: creds.homeserverUrl,
             idBaseUrl: creds.identityServerUrl,
@@ -183,7 +185,8 @@ class MatrixClientPeg {
             deviceId: creds.deviceId,
             timelineSupport: true,
             forceTURN: !SettingsStore.getValue('webRtcAllowPeerToPeer', false),
-            verificationMethods: [verificationMethods.SAS]
+            verificationMethods: [verificationMethods.SAS],
+            unstableClientRelationAggregation: aggregateRelations,
         };
 
         this.matrixClient = createMatrixClient(opts);

src/i18n/strings/en_EN.json

@@ -297,7 +297,7 @@
     "Show recent room avatars above the room list": "Show recent room avatars above the room list",
     "Group & filter rooms by custom tags (refresh to apply changes)": "Group & filter rooms by custom tags (refresh to apply changes)",
     "Render simple counters in room header": "Render simple counters in room header",
-    "React to messages with emoji": "React to messages with emoji",
+    "React to messages with emoji (refresh to apply changes)": "React to messages with emoji (refresh to apply changes)",
     "Enable Emoji suggestions while typing": "Enable Emoji suggestions while typing",
     "Use compact timeline layout": "Use compact timeline layout",
     "Show a placeholder for removed messages": "Show a placeholder for removed messages",

src/settings/Settings.js

@@ -120,7 +120,7 @@ export const SETTINGS = {
     },
     "feature_reactions": {
         isFeature: true,
-        displayName: _td("React to messages with emoji"),
+        displayName: _td("React to messages with emoji (refresh to apply changes)"),
         supportedLevels: LEVELS_FEATURE,
         default: false,
     },