[MM-46980] Improve screensharing permissions flow (#2556)

* Little improvements and simplification

* Improve MacOS screen permissions handling flow

* Add missing error event

* Propagate calls client errors (#2557)

src/main/windows/callsWidgetWindow.test.js

@@ -397,5 +397,10 @@ describe('main/windows/callsWidgetWindow', () => {
             const widgetWindow = new CallsWidgetWindow(mainWindow, mainView, widgetConfig);
             expect(widgetWindow.getURL().toString()).toBe('http://localhost:8065/');
         });
+
+        it('getMainView', () => {
+            const widgetWindow = new CallsWidgetWindow(mainWindow, mainView, widgetConfig);
+            expect(widgetWindow.getMainView()).toEqual(mainView);
+        });
     });
 });