Vulkan: dump summary of commands in digraph This is possible thanks to SecondaryCommandBuffer. Makes life easier when debugging by not just showing resource type in the nodes, but actual stream of commands recorded in each. Bug: angleproject:3136 Change-Id: I125a32ec2966a55330e60930ca088d1a3673a8ba Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1538832 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>