feat(external-api) set `privateMessage` flag on `incoming-message`

modules/API/API.js

@@ -592,8 +592,8 @@ class API {
      * @returns {void}
      */
     notifyReceivedChatMessage(
-            { body, id, nick, ts }: {
-                body: *, id: string, nick: string, ts: *
+            { body, id, nick, privateMessage, ts }: {
+                body: *, id: string, nick: string, privateMessage: boolean, ts: *
             } = {}) {
         if (APP.conference.isLocalId(id)) {
             return;
@@ -604,6 +604,7 @@ class API {
             from: id,
             message: body,
             nick,
+            privateMessage,
             stamp: ts
         });
     }

react/features/chat/middleware.js

@@ -247,6 +247,7 @@ function _handleReceivedMessage({ dispatch, getState }, { id, message, privateMe
             body: message,
             id,
             nick: displayName,
+            privateMessage,
             ts: timestamp
         });