This adds the drmbuf format as a parameter separate from the obs texture
format that will be used. drmbuf's may have a variety of formats that we
need to pass correctly to get a usable texture which may correspond to
multi-platform texture formats.
Implement device_texture_create_from_dmabuf for EGL/X11 and EGL/Wayland.
The code is shared between them, in a new gl-egl-common.c file.
This is currently limited to a few common RGB(A) formats for now, which
seems to cover most use cases.
DMA-BUF is a widespread Linux buffer sharing mechanism. It is what's
commonly used zero-copy screen sharing by Wayland compositors.
Add a new 'device_texture_create_from_dmabuf' vfunc to gs_exports,
and stub implementations to libobs-opengl. Add a new public method
gs_texture_create_from_dmabuf() that calls this vfunc.
