iris: Fix clear color tracking with ISL_AUX_USAGE_GEN12_CCS_E

Add and use a new aux usage which more accurately describes the behavior of CCS_E on gen12. On this platform, writes using the 3D engine are either compressed or substituted with fast-cleared blocks.

Makes iris pass a subtest of the fcc-write-after-clear piglit test (fast-clear tracking across layers 1 -> 0 -> 1) on gen12.

Dependencies:

• Merge dependent MR (the first 4 commits) !4972 (merged)
• Optional: Merge issue reproducer piglit!303 (merged)

/cc @jekstrand