Fix <Extensions> tests by removing mockFs and making everything injectable

Signed-off-by: Sebastian Malton <sebastian@malton.name>

__mocks__/windowMock.ts

@@ -1,19 +0,0 @@
-/**
- * Copyright (c) OpenLens Authors. All rights reserved.
- * Licensed under MIT License. See LICENSE in root directory for more information.
- */
-
-/**
- * Mock the global window variable
- */
-export function mockWindow() {
-  Object.defineProperty(window, "requestIdleCallback", {
-    writable: true,
-    value: jest.fn().mockImplementation(callback => callback()),
-  });
-
-  Object.defineProperty(window, "cancelIdleCallback", {
-    writable: true,
-    value: jest.fn(),
-  });
-}