WebGPU: Implement Renderbuffers Implement the RenderbufferWgpu class. Add the concept of a non-owned webgpu::ImageHelper for supporting EGLImage in the future. Fix some missing texture formats that now get tested with dEQP. Bug: angleproject:418022112 Change-Id: Ie1239ec581e62044e7c8723fc33cb7565d50575c Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6557129 Reviewed-by: Corentin Wallez <cwallez@chromium.org> Commit-Queue: Geoff Lang <geofflang@chromium.org>