Fix RGB565/BGR565 loading functions The BGR565-related loading functions seem to have been defined based on D3D11, especially since D3D11 only has format support for B5G6R5. However, if other backends, such as Vulkan, try to use BGR565, the loading functions do not work as intended. This change aims to correct the loading functions in order to have a single loading methodology for all backends, and to prepare for the future changes that allow the proper usage of B5G6R5 for Vulkan. * Updated the component order in the loading functions related to RGB565 and BGR565. * Updated D3D function map and data related to BGR565 for consistency. * Reverted the PackPixels() exception for RGB565 in Renderer11. * Fixed typo in D3D format data. Bug: b/441803462 Bug: b/409867243 Change-Id: I4d3e497a9435bd65bdf64b527b094267a0353cb8 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6916353 Commit-Queue: Amirali Abdolrashidi <abdolrashidi@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Charlie Lao <cclao@google.com>