Add libcamera support
This PR adds libcamera support to the compression program; V4L2 support isn't retained (though the source files are still there). Libcamera itself is required:
git clone https://git.libcamera.org/libcamera/libcamera.git
cd libcamera
meson setup build
ninja -C build install
Once built, running ./compression
should just pick up the first camera libcamera sees. By default it will run at its highest resolution; you can dial it down by passing a framesize, for example ./compression -s 1280x720