Implement new version of the digital SI

With D-SI version 2.2.0 there were some naming and structural changes: https://gitlab1.ptb.de/d-ptb/d-si/xsd-d-si/-/blob/master/wiki/doc/Updates_2_2_0.md

Moreover, a new SI ontology (SIS) is being created: https://ptb.gitlab.io/dcc/ontology-d-si/ So we should deprecate and replace the previously defined SI-like terms.