Added support for format modifiers in DMA-BUF source

Fixes https://todo.sr.ht/~scoopta/wlrobs/16
Update usage of gs_texture_create_from_dmabuf

As of obs commit 705a47b0e439f649af8a81d0a68d03f3b83ea314 it also
requires a `drm_format` parameter
Moved the screencopy includes into scpy_source.c
Added a notice to the readme about dmabuf breakage
Updated the dmabuf backend for official OBS dmabuf support. This will break it on older OBS EGL forks which do not support gs_texture_create_from_dmabuf().
Fixed memory leak when dmabuf importing is used
Fixed check on wrong EGLImage although it shouldn't technically matter
Added support for dmabuf import when supported by OBS
Added tag v1.0 for changeset bcc570977627
Updated the OBS fork recommended in the readme
If next_frame != NULL when the source is destroyed it now correctly frees the texture
dmabuf_listener is now statically allocated
Removed old info about dmabuf being broken
Fixed the random assortment of issues with dmabuf
Support v3 of wlr-screencopy-unstable-v1

This commit adds support for newer libwlroots, after the merger of
https://github.com/swaywm/wlroots/pull/2133
Make library install-able
Added note about QT_QPA_PLATFORM=xcb
scpy_source and dmabuf_source are now extern
Added support for specifying a region to capture
dmabuf should be auto-disabled if dependencies can't be met
Next