Feature: Extract ontology internal mappings

[syphax-bouazzouni]

Includes

• Refactor: Split mappings_ontologies method to small functions #159

Why

Ontologies define mappings on their own, using mappings predicates like skos:exactMatch, skos:relatedRelation, owl:sameAs,... But we don't show them in the ontology/concept/class mappings endpoints.

How

We define a list of mapping predicates to extract in the internal_mapping_predicates currently in this PR, it is

      predicates["SKOS:EXACT_MATCH"] = ["http://www.w3.org/2004/02/skos/core#exactMatch"]
      predicates["SKOS:CLOSE_MATCH"] = ["http://www.w3.org/2004/02/skos/core#closeMatch"]
      predicates["SKOS:BROAD_MATH"] = ["http://www.w3.org/2004/02/skos/core#broadMatch"]
      predicates["SKOS:NARROW_MATH"] = ["http://www.w3.org/2004/02/skos/core#narrowMatch"]
      predicates["SKOS:RELATED_MATH"] = ["http://www.w3.org/2004/02/skos/core#relatedMatch"]

Future contribution is to make this variable in the config files

These mapping predicates will then be added to the mapping SPARQL query