[enhancement] Add commands to cancel previous work

There are usecases where it would be beneficial to cancel previous stale workload in the queue. That could improve latency, responsiveness, and save some watts.

I imagine it could be something like a `vkQueueCancelWork( VkQueue queue )`, which would be the same as `vkQueueWaitIdle` except it does not care if the work in the queue was executed. If this could be done at Fence granularity, then even better.

Is this something that would be feasible on some GPUs?

No files, tests, or entry points are mentioned. Start by reviewing the proposed queue and fence cancellation behavior and the surrounding Vulkan specification requirements; done would require an agreed API design and documented feasibility.

Written by the indexing model from the issue text.