Many GLAMOR OpenGL ES Improvements Backported To X.Org Server / XWayland 21.1

Nearly one year after the merge request was first opened, back-ported now to the X.Org Server 21.1 stable branch are a number of GLAMOR 2D acceleration fixes around OpenGL ES 2.x as well as supporting OpenGL ES 3.x shaders for this generic 2D acceleration over OpenGL for the xorg-server and XWayland...