feat: emit raise hand event to external API (#8312)

* Expose raise hand event to external application

* Fix linting issues

* fix the app non existing issue

modules/API/API.js

         });
     }
 
+    /**
+     * Notify external application (if API is enabled) that user updated their hand raised.
+     *
+     * @param {string} id - User id.
+     * @param {boolean} handRaised - Whether user has raised hand.
+     * @returns {void}
+     */
+    notifyRaiseHandUpdated(id: string, handRaised: boolean) {
+        this._sendEvent({
+            name: 'raise-hand-updated',
+            handRaised,
+            id
+        });
+    }
+
     /**
      * Disposes the allocated resources.
      *

modules/API/external/external_api.js

     'participant-role-changed': 'participantRoleChanged',
     'password-required': 'passwordRequired',
     'proxy-connection-event': 'proxyConnectionEvent',
+    'raise-hand-updated': 'raiseHandUpdated',
     'video-ready-to-close': 'readyToClose',
     'video-conference-joined': 'videoConferenceJoined',
     'video-conference-left': 'videoConferenceLeft',

react/features/base/participants/middleware.js

         raisedHand
     }));
 
+    if (typeof APP !== 'undefined') {
+        APP.API.notifyRaiseHandUpdated(participantId, raisedHand);
+    }
+
     if (raisedHand) {
         dispatch(showNotification({
             titleArguments: {

react/features/toolbox/components/web/Toolbox.js

      */
     _doToggleRaiseHand() {
         const { _localParticipantID, _raisedHand } = this.props;
+        const newRaisedStatus = !_raisedHand;
 
         this.props.dispatch(participantUpdated({
             // XXX Only the local participant is allowed to update without
 
             id: _localParticipantID,
             local: true,
-            raisedHand: !_raisedHand
+            raisedHand: newRaisedStatus
         }));
+
+        APP.API.notifyRaiseHandUpdated(_localParticipantID, newRaisedStatus);
     }
 
     /**