Using the same scheme as we do for VkImageViews we can track VkSampler
lifetime using SharedResourceUse. This fixes the race condition that
could occur when samplers are deleted in one Context while being used
in another.

This fixes the last known resource lifetime issue. The multithreading
tests should now pass without validation errors.

Also adds regression tests to angle_end2end_tests.

Bug: angleproject:2464
Change-Id: I9dbed5062a0863b240ddf1a9b5d28560334934de
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1869548
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Ian Elliott <ianelliott@google.com>
Reviewed-by: Tim Van Patten <timvp@google.com>