Can't import two datasets with the same name

[craig-willis]

Bug or feature?

As noted in #510 (review), if I import two datasets with the same name, the previous import is clobbered:

For example:

• https://girder.local.wholetale.org/api/v1/integration/deriva?url=https%3A%2F%2Fpbcconsortium.s3.amazonaws.com%2Fwholetale%2F5ad7cdf55b0d5007601015b7ff1ea8d6%2F2021-11-09_21.47.58%2FDataset_1-882P.zip&force=false
• https://girder.local.wholetale.org/api/v1/integration/deriva?url=https%3A%2F%2Fidentifiers.fair-research.org%2Fhdl%3A20.500.12633%2FUzn848Mmg1Wk
• Download one of the above zipfiles and import manually
• In all cases, the same dataset record is updated
• (I still need to test, but does this also happen with DV/Zenodo).

Expected results*
When I import two different versions of an exported Deriva bag or if I register one and import the other as a raw zip, I expect them to be treated differently. I thought that setting the dataset identifier would disambiguate.