Port WebGL Wasm conformance tests to WebGPU

[kenrussell]

Test cases uploading from large WebAssembly heaps to WebGL were added under https://github.com/KhronosGroup/WebGL/tree/main/sdk/tests/conformance2/wasm in order to expose and prevent bugs in web engines' validation of large offsets into ArrayBuffers and ArrayBufferViews.

Based on feedback from a couple of colleagues, similar bugs might exist in WebGPU implementations. These tests should be ported over to the WebGPU API to catch such bugs and act as regression tests.