Fixing glClear tests. This CL makes a few changes to fix up the basic glClear test RGBA8Framebuffer, as well as adding a test that uploads a texture before clearing a RGBA8 framebuffer. It moves the wgpu::RenderPassDescriptor(RPD), as well as helper methods for comparing RPDs from the context to the framebuffer. The color attachments that are created in when FramebufferWgpu::clear is called are also stored in the framebuffer now as well. This CL also changes texture creation to use the RGBA8Unorm format instead of RGBA8Uint format. It also adds the wgpu viewFormats parameter to an ImageHelper. Future formats support is still TBD. Bug: angleproject:8582 Change-Id: Idfc4182eb4d6de8a771f2f91d337564ee71df010 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5503549 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Matthew Denton <mpdenton@chromium.org> Commit-Queue: Liza Burakova <liza@chromium.org>