temp/libcamera: add legacy udev rule package
When we switched to udmabuf in 014fdc1d, we also switched away from groups to the in various ways superior uaccess mechanism.
While most DEs support this via (e)logind, there are some DEs - most importantly Sxmo - which do not. Add a package with legacy rules that gets installed if neither login implementation is installed so cameras work for there, too.
Includes temp/libcamera: actually apply udev rule (!6090 - closed)