Store alternate type information in addition to Biolink types

[gaurav]

A lot of our identifiers have very specific type information -- for example, UMLS includes semantic types that are much more specific than Biolink. It might be useful to keep that information somewhere and include it in the same way we include descriptions -- for example, @StevenGuo42 has found that UMLS types are more useful than Biolink types when doing NER on UMLS IDs.