Change typing for after/before window/application start (#7342)

- Now the callback is provided with an object containing either
  `mainDi` or `windowDi` fields. This should help with confusion
  over which environment the `di` is for

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

packages/core/src/features/extensions/navigation-using-application-menu.test.ts

@@ -19,7 +19,7 @@ describe("extensions - navigation using application menu", () => {
   beforeEach(async () => {
     builder = getApplicationBuilder();
 
-    builder.beforeWindowStart((windowDi) => {
+    builder.beforeWindowStart(({ windowDi }) => {
       focusWindowMock = jest.fn();
 
       windowDi.override(focusWindowInjectable, () => focusWindowMock);