[WebGPU] Implement validation for getBindGroupLayout https://www.w3.org/TR/webgpu/#dom-gpupipelinebase-getbindgrouplayout
<rdar://problem/110688660>
Pull request: https://github.com/WebKit/WebKit/pull/14906
Committed 265139@main (79d919888cc9): <https://commits.webkit.org/265139@main> Reviewed commits have been landed. Closing PR #14906 and removing active labels.