[BUGFIX] Tweaks and fixes to ``security:showeffectivepolicy`` command
This change removes some left-over references to the
``PrivilegeVoteResult`` class that no longer exists.
Besides this renames the "role-identifiers" parameter to "roles" and
expands those roles in order to cover parent roles, too.
Lastly this fixes support for custom privilege types allowing the
"privilege-type" parameter to refer to any class implementing
Releases: master, 3.0