layers: Record 3D image slice layouts

layers: Record 3D image slice layouts

Fixes a bug in image layout state handling that appeared with
khr_maintenance1. When a 3D image which was created with the
VK_IMAGE_CREATE_2D_ARRAY_COMPATIBLE_BIT_KHR flag is transitioned
between layouts, we now also record a transition for each depth
slice, treating it as an array layer subresource.

The actual fix is just two lines within TransitionImageLayouts().
Also included are some debug-enabling refactoring to distinguish
layout state updates vs additions, and support for new aspect
mask bits.

Change-Id: Ibb5131a6dba8fcdeafe5e6d94af2decf751842ec