Rename Bulk WES -> Bulk DNA-Seq

[inodb]

For HTAN some of the data is targeted, some WES, some WGS. We are currently doing a rename on the HTAN portal, so it's not urgent but would be nice to fix in the model itself

As Adam Taylor pointed out: it would be even better if we could use EFO terms: https://www.ebi.ac.uk/ols/ontologies/efo/terms?iri=http%3A%2F%2Fwww.ebi.ac.uk%2Fefo%2FEFO_0002693