core: fallback to applicationName

The commit adds handling to fallback to the `applicationName` when setting the window title which would previously display either `index.html` in electron  or `localhost:3000` in the browser.

Signed-off-by: vince-fugnitto <vincent.fugnitto@ericsson.com>

packages/core/src/browser/window/window-title-service.ts

@@ -100,7 +100,7 @@ export class WindowTitleService {
         if (developmentHost) {
             this._title = developmentHost + this.separator + this._title;
         }
-        document.title = this._title;
+        document.title = this._title || FrontendApplicationConfigProvider.get().applicationName;
         this.onDidChangeTitleEmitter.fire(this._title);
     }