Vulkan: Clean up "actual"/"intended" naming. Clarifies that the GL internal format is an "intended" format and the Vulkan formats are "actual" formats. This makes all the format fields use the same consistent naming pattern. Bug: angleproject:5438 Change-Id: I935a49895109e9e06eae5ef98d5614dfd1128ff8 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2605728 Reviewed-by: Tim Van Patten <timvp@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>