Add more helper methods for textures. This change adds a DisplayWgpu member variable to ContextWgpu as well as a getter for the display so other objects can access a webgpu device. This change also adds helper methods to translate GL texture information (size, dimension, mip level count, etc.) to webgpu compatible texture information. Bug: angleproject:8547 Change-Id: Ifb2c5d021b1cbb95304a732c57d3250f1731496b Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5385574 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Matthew Denton <mpdenton@chromium.org> Commit-Queue: Liza Burakova <liza@chromium.org>