MALTDS-91 : Make RPM-based Kerberos configuration more modular

The current RPM-based solution for configuring the Kerberos client on C8 is not flexible enough, this is causing issues especially for IPA support of the Kerberos Puppet module (MALTDS-8).

This merge request also enables principal canonicalisation for realm IPA-DEV.CERN.CH (MALTDS-88) and adds tests.