Rework compressed texture pixel unpack state handling. Compressed images do not use the pixel unpack parameters. Instead of handling this in Context, move this to formatutils, where it's already handled for the 2D case. Also, update the test to generate an ASAN error if not ignored for the 2D case. Bug: chromium:1267496 Change-Id: Ib93bae00a2b0b75eafd74c267f737da225afd993 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3308825 Commit-Queue: Jonah Ryan-Davis <jonahr@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>