Adding OMIM information to genes in assay facts

[afrubin]

Gene names in the assay facts blocks should be formatted as links to OMIM.

The OMIM ID is available in the RefSeq structured data under the key omimIds and is provided as a string. This can be formatted as a URL (e.g. https://omim.org/entry/113705 would have "113705" in the RefSeq data).

To implement this we should:

• Add OMIM ID to the https://api.mavedb.org/api/v1/hgvs/genes/ endpoint
• While we're at it, we should also add the RefSeq gene ID
• Update the UI for the assay facts to format the gene name as an OMIM link

Optionally we should consider:

• Changing from the RefSeq gene summary to the OMIM description since these are likely to be higher quality