Picks up several breaking changes, including the switch to unwrapped BOOL properties.

…#5289)

This PR configures the underlying HTMLVideoElement used by the plugin so it triggers a `VideoEventType.initialized` both for `canplay` (current behavior) and `loadedmetadata` events (fixes iOS 17).

It also sets `src` as the last configuration value when creating the VideoElement, which is common practice when listening to events from HTMLElements, like `img` or even `iframe`s.

### Issues

* Fixes: **P1** flutter/flutter#137023

### Tests

* Added a small integration test to ensure `loadedmetadata` triggers the expected VideoPlayer event.
* Deployed changes to: https://dit-videoplayer-tests.web.app for manual verification on an actual iOS device.

* Enables [**FedCM API**](https://developer.mozilla.org/en-US/docs/Web/API/FedCM_API) on compatible browsers.
  * The GIS JS SDK falls-back to the JS implementation on browsers that don't support the new standard. See [migration instructions](https://developers.google.com/identity/gsi/web/guides/fedcm-migration)).
* Uses the supplied token expiration information to **more accurately compute `isSignedIn()` and `canAccessScopes(scopes)`**.
  * This does not handle the case where users sign in/out in another tab or from outside the web app, that's still something that needs to be checked server-side.
* **Deprecates the `signIn()` method on the web.**
  * Users should migrate to a combination of `renderButton()` and `silentSignIn()`, as described [here](https://pub.dev/packages/google_sign_in_web#migrating-to-v011-and-v012-google-identity-services).

### Issues

* FedCM:
  * Fixes flutter/flutter#133703 (once rebuilt/redeployed)
  * Fixes `b/301259123`
* Token expiration:
  * Unblocks `b/245740319`

### Testing

* Added a few unit tests
* Manually verified token expiration: https://dit-gis-test.web.app