Add content-type endpoint for updating template instances
This MR adds a content-type endpoint for updating template instances. Data types of literal values are automatically assigned, based on the template.
Literal validation:
- If the data type is a known XSD data type, it must also match the XSD data type specific constraints (i.e. "true" or "false" for a boolean).
- If the template property is of a custom literal type, the URI of that class is assigned and no validation, other than the template property pattern validation, takes place.
- If the class has no URI, xsd:string is used as a fallback.
The literal validation logic could also be re-used in the literal service.
Edited by Marcel Konrad