feat(external-api): Add recording download link available event (#10229)

modules/API/API.js

@@ -1458,6 +1458,20 @@ class API {
         });
     }
 
+    /**
+     * Notify external application (if API is enabled) that the current recording link is
+     * available.
+     *
+     * @param {string} link - The recording download link.
+     * @returns {void}
+     */
+    notifyRecordingLinkAvailable(link: string) {
+        this._sendEvent({
+            name: 'recording-link-available',
+            link
+        });
+    }
+
     /**
      * Notify external application (if API is enabled) that a participant is knocking in the lobby.
      *