Also, let's move the glue for this to src/shared/ so that we later can
reuse this in sysemd-firstboot.
Given that libpwquality is a more a leaf dependency, let's make it
runtime optional, so that downstream distros can downgrade their package
deps from Required to Recommended.
There's some highly specific PKCS#11 code in homectl.c. Let's split that
out, since it is easily isolatable, to make homectl.c a bit more
readable.
No funcional changes, just some moving around and renaming two functions
to make them more suitably named when exported.
Lennart Poettering