ggml-webgpu: compute pass batching and removing profiling overhead (ggml-org#21873)

* Update register tiling matmul to use f32 accumulation

* fix profiling code

* Fix register tiling matmul for chrome, i'm blaming dawn

* Update batch tuning value for iOS

* compile fix

* Fix use of new load function

* Move to a single query set for GPU profiling

* Move to batching compute passes when not profiling

* Refactor build_multi

* remove iOS throttling now that we're batching compute passes

Author: reeselevine