install: -Z gives new files and directories a different SELinux type than GNU #15091

With -Z, GNU install gives new files and directories the default context from the SELinux policy, as mkdir -Z and cp -Z do (in uutils too). uutils install derives it from the parent directory's context instead, and turns any type containing tmp into user_home_t.

On Fedora with SELinux enforcing, as a normal user:

$ install -Z f /tmp/f; install -d -Z /tmp/d; ls -Zd /tmp/f /tmp/d

GNU coreutils 9.12: /tmp/f is user_tmp_t, /tmp/d is tmp_t. uutils main: both are user_home_t.

mkdir -Z and cp -Z in uutils already agree with GNU. Under a home directory all of them give user_home_t, which is probably why the GNU install-Z-selinux test passes.