[Request][JSS Legacy API] - JSS::LDAPServer object creation

While building some automation, it would be nice to be able to create the `JSS::LDAPServer` object(s). Right now it does not include the `JSS::Creatable` mix-in which prevents it from properly being created. Additionally it does not have a `RSRC_LIST_KEY` set, so that would need to be set as well.