MM-52857 - Add call-join-request to calls widget (#2751)

* add call-join-request to calls widget

* targetID -> callID

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

src/main/preload/mattermost.js

@@ -36,6 +36,7 @@ import {
     CALLS_WIDGET_SHARE_SCREEN,
     CLOSE_DOWNLOADS_DROPDOWN,
     CALLS_ERROR,
+    CALLS_JOIN_REQUEST,
 } from 'common/communication';
 
 const UNREAD_COUNT_INTERVAL = 1000;
@@ -352,6 +353,16 @@ ipcRenderer.on(CALLS_ERROR, (event, message) => {
     );
 });
 
+ipcRenderer.on(CALLS_JOIN_REQUEST, (event, message) => {
+    window.postMessage(
+        {
+            type: CALLS_JOIN_REQUEST,
+            message,
+        },
+        window.location.origin,
+    );
+});
+
 /* eslint-enable no-magic-numbers */
 
 window.addEventListener('resize', () => {