Compressed layout is back (maybe?)

[albyrock87]

Description of Change

In Xamarin using CompressedLayout.IsHeadless="True" literally changed the performance of our app from "laggy" to "snappy" on Android :)

This is just a proof-of-concept to show how compressed layout support could look like in MAUI and if adding such support would increase the performance or not.

Test case	First render	BindingContext changes	Clear
iOS main	1316ms	166.2ms	46.4ms
iOS PR	1225ms	118.4ms	123.8ms
Android main	533ms	55.4ms	34.6ms
Android PR	433ms	50.2ms	30.2ms

I still don't understand the reason behind slow Clear on iOS, especially because that PlatformView.ClearSubviews() didn't change.

Also, I've not implemented the InvalidateMeasure part, on which I feel there would be additional considerations.

Anyway, before going further with this one, I wanted to double-check with you if this will ever be taken in consideration.

[dotnet-policy-service]

Hey there @albyrock87! Thank you so much for your PR! Someone from the team will get assigned to your PR shortly and we'll get it reviewed.