`HasKeyboardHandlerComponents` should be replaced a `KeyboardEventsDispatcher`

[spydon]

What could be improved

Similarly to the MultiTapDispatcher a similar one should be created for keyboard events.

Why should this be improved

So that the user doesn't have to manually add the HasKeyboardHandlerComponents mixin to their game.

Any risks?

No, it will be a breaking change though, but very simple for the user to migrate since they'll just have to remove the mixin.