Generate form editor objects from targetClass and not shape name

[jsheunis]

The current implementation of gen-shacl gives a sh:nodeShape the same name as the LinkML class that it was generated from; and then assigns the same as the targetClass

e.g.:

dldist:Person a sh:NodeShape ;
    sh:closed true ;
    ...
    sh:targetClass dldist:Person .

For SHACL-based validation purposes, the sh:targetClass specifies the target, and not the name of the nodeshape. The example could just as well have been:

dldist:MyPersonShape a sh:NodeShape ;
    sh:closed true ;
    ...
    sh:targetClass dldist:Person .

The form should show the name of the field as "dldist:Person" and not "dldist:MyPersonShape". The current shacl-vue code in https://github.com/psychoinformatics-de/shacl-vue/blob/main/src/composables/shapedata.js uses the nodeshape name, i.e. this has to be corrected to use sh:targetClass

Relevant LinkML issue: linkml/linkml#2084, which suggests using a shape annotation to redefine the name of the nodeshape in the exported shacl. This is strictly not necessary here, since a shift to using the sh:targetClass will in any case ignore the nodeshape name.

An important additional aspect to note from the SHACL standard is Implicit Class targets:

Informally, if a shape is also declared to be a class in the shapes graph then all SHACL instances of this class are a target for the shape.

I interpret this to mean the following

• a sh:nodeshape might not always have sh:targetclass defined (the target is actually orthogonal to class, since there are different types of shacl targets: https://www.w3.org/TR/shacl/#targets (TODO: shacl-vue code needs to take this into account))
• if a sh:nodeshape does not have a target defined (and here, more concretely a sh:targetclass), then see if the same nodeshape is also defined as a rdfs:Class in the same shapes graph: if true, use the shape name as the sh:targetclass