main/eudev: move all config under /usr

This moves everything but the binaries which are in /bin and /sbin to the /usr hierarchy. It keeps "--enable-split-usr", which according to documentation it hardcodes looking for rules and binaries under "/" and "/usr". However, it now only reads .hwdb files from /usr/lib, so the follow-up commits will move every package that installs them under /lib/udev/hwdb.d

Depends !72695 (merged)