Migrate Effect Lexicon to Sequence Ontology

[awenocur]

Recent versions of SnpEff default to using strings from the Sequence Ontology to identify types of effects, rather than using the SnpEff-specific EffectType enum names.

Eventually, the importer should be able to identify effects based on the Sequence Ontology strings. Ideally, there should be a way of recognizing effects based on either nomenclature, as they are mutually exclusive when evaluated in a case-sensitive manner, and unambiguous even when ignoring case.

It won't be as simple a matter as adding duplicate entries in the effect table, as the Sequence Ontology strings should map to the same entities as the corresponding classic strings.