Add support for WebGPU texture component swizzle

[mvaligursky]

Feature

Add support for texture component swizzle, shipped in Chrome 143.

This allows rearranging or replacing a texture's RGBA channels at access time via a swizzle specification (each output channel mapped from r/g/b/a/0/1), configured on the texture view. The engine does not currently expose or apply component swizzles.

Benefit

• Adapt source texture channel layouts (e.g. BGRA vs RGBA, single-channel broadcast, fixed 0/1 channels) without extra shader code or format conversions.
• Simplifies handling of imported/compressed textures whose channel order differs from what shaders expect.

Notes

• Requires plumbing a swizzle option through texture/texture-view creation and a capability check for support.
• Ref: https://developer.chrome.com/blog/new-in-webgpu-143