This file contains the Pipeline and RenderPass cache utils.

Also renames renderervk_utils.h to vk_utils.h and the format utils
file.

Refactoring change only.

Bug: angleproject:2163
Change-Id: I5113a9a2c6f0b0960d38e6c2d8e391fa2d9f5f6a
Reviewed-on: https://chromium-review.googlesource.com/876505Reviewed-by: Frank Henigman <fjhenigman@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>