express single-value props as `owl:FunctionalProperty`

cim:GeneratingUnit.maxEconomicP
        rdf:type           rdf:Property ;
        cims:multiplicity  cims:M:0..1 ;

[x] fix M:1 to M:1..1 for uniformity
[x] For props with cims:multiplicity cims:M:0..1 and cims:M:1..1, add rdf:type owl:FunctionalProperty
- This is done for v3.0 and for 0..1, should check for 1..1 and do it for v2.3
[x] For their inverses, add rdf:type owl:InverseFunctionalProperty
[x] Keep the cims:multiplicity annotation for easy reference, and because it has more info
This doesn't mean that your RDFS ontologies become OWL: it is just a standard way to express "single-valued" props.

Sveino / Inst4CIM-KG