Bugfix/autoscale on fullscreen

[thet]

pat-auto-scale elements within pat-fullscreen were not correctly resized after fullscreen was activated/deactivated.
an attempt would be to

1. await screenful.request and screenful.exit or resolve their promises and throw a custom event afterwards, wich pat-auto-scale can listen to to re-scale,
2. listen to a screenful event in pat-auto-scale (not sure, if that exists),
3. debounce re-scale for 300ms after screenful request/exit.

However, these changes here seem to fix that problem too.
And it's not that i removed immediate=true from the debounce call.