Don't package private library and typelib files separately.

The cinnamon-screensaver package is already arch-specific, and libcscreensaver isn't used outside of this package. The libcscreensaver0 package will remain as an empty transitional package. ref: https://github.com/linuxmint/cinnamon/pull/11999 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1059341#15