libcasper: Move everything to the libcasper package
The libcasper package exists to contain libcasper, but for some reason
only the libcap_net service was in the package, with libcasper itself
and the rest of the services being in runtime. Move everything to the
libcasper package, except tests which stay in the tests package.
MFC after: 1 day
Reviewed by: emaste
Sponsored by: https://www.patreon.com/bsdivy
Differential Revision: https://reviews.freebsd.org/D53576
(cherry picked from commit b8697ac70ebfce2d8e3df6c67bbf37910793b199)