ggml webgpu: profiling, CI updates, reworking of command submission (llama/16452)

ggml webgpu: profiling, CI updates, reworking of command submission (llama/16452)

* Add profiling

* More detailed profiling

* Rework command submission to avoid global locks

* Update wait handling

* try new method of waiting on futures

* Add serializing of command submission in some cases

* Add new pool for timestamp queries and clean up logging

* Serialize command submission in CI and leave a TODO note

* Update webgpu CI

* Add myself as WebGPU codeowner

* Deadlock avoidance

* Leave WebGPU/Vulkan CI serialized

* Fix divide by 0

* Fix logic in division by inflight_threads

* Update CODEOWNERS and remove serialize submit option