Use SamplerID in place of GLuint handles Update all Sampler handles to type SamplerID, preparing for midframe capture of sampler. Bug: angleproject:3804 Change-Id: I9337919f97d61e28718987612d642c569b90246a Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1761780 Commit-Queue: Jiacheng Lu <lujc@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org>