Vulkan: refactor CommandGraphResource Merged back RecordableGraphResource into CommandGraphResource. Queries didn't really need to be a resource, as they always inserted separate single-command nodes in the graph. The CommandGraph class is augmented with a few functions that generate such nodes. This is in preparation for debug markers, as they too require such nodes. Bug: angleproject:2853 Change-Id: I5251a0e0fdd42ed1126921b4acc13687a14af9cd Reviewed-on: https://chromium-review.googlesource.com/c/1422549 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>