Separate taxon relations into species interaction and taxon concept relations

[mdoering]

It will be cleaner to separate out species interactions and taxon concept set relations. Species interactions also benefit from additional properties as the related species often are not part of the datasets taxa, but rather annotated verbatim names.

The proposal therefore is to replace TaxonRelation with

TaxonConceptRelation

• same properties as the current TaxonRelation

SpeciesInteraction

• taxonID - always points to a taxon of the local dataset
• relatedTaxonID - either a local taxonID, an external URI or null if just a relatedTaxonScientificName is given
• relatedTaxonScientificName - required in case relatedTaxonID is null or external. With authorship if known
• type - there needs to be a reverse-type for each interaction-relationship type
• referenceID - reference for taxon interaction
• remarks - interaction remarks

[mdoering]

Related taxa with just a scientificName can be dynamically linked in the CoL Clearinghouse to a) all datasets that treat the name or b) a specific dataset if the registered dataset is configured to do so (manually in dataset settings or inside the archive via coldps metadata.yaml)