SF: Consolidate layer-to-output filtering

Add ui::LayerFilter for less repetitive CE plumbing. Make ui::LayerStack
a type, and (unlike the alias) use it everywhere. Remove redundant state
in CE's DisplayCreationArgs.

Bug: 182939859
Test: Display cutout is excluded in screenshots.
Test: libcompositionengine_test
Test: libsurfaceflinger_unittest
Test: SurfaceFlinger_test
Test: libgui_test
Change-Id: Ib854d354af7aef7168001c34297e875b71d53622