Vulkan: Refactor ImageCopy shader - Refactor common shader code into "ImageCopy.inc" - Add ImageCopyFloat shader that supports only float src and dst formats - Perform YUV and multisampled image copies with ImageCopyFloat Bug: angleproject:372059358 Change-Id: I34bbaf49f98920494d9ed9e1fd290b413a89ea13 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5927276 Commit-Queue: mohan maiya <m.maiya@samsung.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>