When adding a Resource to the ResourceUseList of ContextVk
we constructed a new SharedResourceUse object for tracking
and update of the Resource's Serial. We would then delete
it after releasing the resource. This incurs repeated
memory operation costs.

Instead we now allocate a pool of SharedResourceUse objects
and acquire and release from this pool as needed.

VTune profile of the Manhattan 30 offscreen benchmark
shows the CPU occupancy of bufferRead decrease from an
average of 0.9% -> 0.6% and imageRead decreases from
an average of 0.4% -> 0.3%. The bottleneck for both
these methods is the retain() method that leverages
the new SharedResourceUse pool.

Bug: angleproject:4950
Change-Id: Ib4f67c6f101d4b2de118014546e6cc14ad108703
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2396597Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Mohan Maiya <m.maiya@samsung.com>