This is similar to the `entityhub:site` property added by the EntityhubLinkingEngine.
As the FST linking engine does work with any SorCore this engine will not use `entityhub:site` but `fise:origin` instead. This property will be added to all `fise:TextAnnotation` instances created by this engine.
Configuration of the origin is done by using the `enhancer.engines.linking.lucenefst.origin` property. A single value can be configured as String. If the value is an absolute URI an UriRef value will be parsed. In other cases the value will be a Literal.