add DRI createImageWithModifiers2
This breaks out the new DRI interface from !3197, as we have consensus that having DRI usage flags in addition to the modifier is something we need to properly describe some use-cases and unlock some optimizations. It also adds a helper around the various ways we now have to create a DRI image to get rid of code duplication in the various winsys.
I hope that this is a suitable base for both !4460 and !7603.