For every attribute path in a schema, I can ...
- define 0 or 1 sub-schema by selecting from a list of existing schemata
- the sub-schema is referenced by ID, but can be displayed in the UI via its class (for the moment we allow only one schema per class as a simplification)
- if a subschema is selected there is a link to edit the subschema
OPTIONAL (decide if already part of this ticket):
- define 0 or 1 value-types (for literals)
- display analog. to sub-schema selection, but without editing link
- value-types are (for now) offered from an internal hardcoded list ("xsd:int", "xsd:year", ...)
- if no sub-schema or value-type is defined, the "value type" states "Allow any value type"
A mockup is linked to this ticket.