feat(Youtube Player): view loading status and load programmatically

### Feature Description

Since the ready event is not fired anymore (https://github.com/angular/components/issues/28834), I would like to know if the player has been loaded yet or not (still showing placeholder). Is there already an api for that? If so I did not find it.

Furthermore it would be great if there were a way to programmatically load the player.
(The load method is currently private to the player component.)

"Dirty" workaround:
I am accessing the placeholder via css selectors and dispatching a click event on them in order to trigger the player load.

### Use Case

Example use case: UI Button that will trigger the player to play.
=> The button label may change depending on the loaded status and the click might trigger the player to load and start.

_PS: Thanks for the wrapper component. 🙏_

Commencez par le composant Youtube Player et sa méthode load actuellement privée, en utilisant l’issue liée sur ready-event comme contexte. Définissez l’achèvement comme un moyen exposé de déterminer si le Player est chargé et comme un moyen public de le charger par programmation, prenant en charge le cas d’utilisation du bouton décrit.

Rédigé par le modèle d'indexation à partir du texte de l'issue.