Bug: Fixes x-model.fill when used with debounce

[ekwoka]

Fixes #4102

due to how debounce influenced the handling of the fill event, the model would clear out the input value before the event would be handled.

demo here

This instead just directly uses the same methods to update the value. These methods hadn't existed before, which is why the event was used before.

This isn't amazing, since it does not use any real Events, since it's impossible to make a real Event with a target value, and I was aiming for a minimal impact change.

Test is included.

[calebporzio]

Ok, that makes sense to me to just set that value directly instead of firing an event

[bb]

Thank you, both!

[ekwoka]

@calebporzio Yes, originally, it used the event, due to how the logic for modifiers like number and different elements was handled in a way that wasn't able to be easily set directly.