UMLS API: Allow specifying version of file to be downloaded

[dogversioning]

Problem Statement
Right now, the UMLS api downloads the latest version of a data set 100% of the time.

It would be useful for data verification reasons to be able to run studies against specific vintages of external data

Desired behavior
The module calling the API should accept a string targeting a specific version, and use that to fetch it.

Optionally, the module could provide a list of available modules and/or do some validation of expected values, though there would be several formats depending on which resource type is being fetched

Additional context
None