Support for additional synonym levels

[azankl]

The Human Phenotype Ontology (HPO), the Uberon ontology, and other OBO ontologies support multiple synonym levels, as described here:
https://github.com/obophenotype/uberon/wiki/Using-uberon-for-text-mining

It would be great if INCEpTION could not only support additional synonym levels, but also consider them differently when ranking the candidates shown to the user (i.e. exact synonyms should rank higher than broad, narrow or related synonyms).