Fix favourites (& probably some more inherited stuff) broken by TypeScript conversion

Note that any properties declared in a sub-class aren't generally available until after the super() call is done, i.e. in the super constructor they're undefined.

api/js/jsapi/egw_app.js

@@ -50,11 +50,12 @@ var EgwApp = /** @class */ (function () {
      * Initialization and setup goes here, but the etemplate2 object
      * is not yet ready.
      */
-    function EgwApp() {
+    function EgwApp(appname) {
         /**
          * Mailvelope "egroupware" Keyring
          */
         this.mailvelope_keyring = undefined;
+        this.appname = appname;
         this.egw = egw(this.appname, window);
         // Initialize sidebox for non-popups.
         // ID set server side