Update TOPMed study list.

[jonathancrabtree]

The current TOPMed study list was culled from the dbGaP link/search specified on the main TOPMed page:

https://www.ncbi.nlm.nih.gov/gap/?term=topmed

The current list (embedded in the DATS conversion code) contains 19 studies, but the query now returns 20, suggesting at least one is missing. It's also possible that there are TOPMed studies not returned by the query, so ideally the full project/study list should be cross-referenced against dbGaP:

https://www.nhlbiwgs.org/group/project-studies

[bheavner]

There's ambiguous and confusing nomenclature here about "study" vs. dbGaP accession vs. "TOPMed project". A given TOPMed project may include multiple "Parent Studies", each of which may have multiple dbGaP accession numbers. There is not a 1:1 correspondence between dbGaP Accession and "TOPMed Study". See Section II of the whitepaper, here: https://docs.google.com/document/d/1e77a7dZ9I1FcXHbK-CXkbXmP5xywsw1dePsoxX_E6OM/edit#heading=h.qv33lvfbuhy