WebGPU: Generate texture formats when initializing surfaces. Bug: angleproject:344814096 Change-Id: I873c6308e9c203fd759ccbf5a378056f2aca849c Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5763218 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Liza Burakova <liza@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>