Add test cases of uniform* from Wasm heap

[kenrussell]

Per discussion with aswan from Figma on the WebGL Dev+Implementer chat, there may be bugs in various browsers' implementations of uniformMatrix3fv and related entry points when called with a very large ArrayBuffer or Float32Array (such as that from the Wasm heap), large offsets, and small lengths.

The tests in https://github.com/KhronosGroup/WebGL/tree/main/sdk/tests/conformance2/wasm should be extended to test the uniform* entry points.