link ec:Action in EBUCorePlus schema

[wivaku]

The schema includes ec:Action but it seems it is not referenced by other classes.
We believe the below makes it available to an EditorialObject or MediaResource (see #497).
In addition, ec:Action has hasRelatedScene, but we feel it makes more sense to have ec:hasRelatedSegment.

ec:hasActions a owl:ObjectProperty .

ec:EditorialObject a owl:Class ;
    rdfs:subClassOf [
        a owl:Restriction ;
        owl:onProperty ec:hasActions ;
        owl:allValuesFrom ec:Action
    ] .

ec:MediaResource a owl:Class ;
    rdfs:subClassOf [
        a owl:Restriction ;
        owl:onProperty ec:hasActions ;
        owl:allValuesFrom ec:Action
    ] .

# similar to (and: instead of) hasRelatedScene
ec:hasRelatedSegment rdf:type owl:ObjectProperty ;
                   dcterms:description "To associate a concept with a Segment"@en ;
                   rdfs:label "Related segment"@en .

ec:Action a owl:Class ;
    rdfs:subClassOf [
        a owl:Restriction ;
        owl:onProperty ec:hasRelatedSegment ;
        owl:allValuesFrom ec:EditorialSegment
    ].