Update FreeBSD Dockerfiles

1. sort packages alphabetically
2. try to bring in some feature parity between the Qt5 and Qt6 image (pyside6, bsdisks, kimageannotator...)
3. use kseepxr (kde fork) instead of seexpr
4. use renamed origins for polkit-qt, libaccounts-qt and signond

[the builder is stilll building byside6, repo should be updated soon]