feat: add support for dataset ref names in a run

[alkasm]

You can pass file paths to upload or a list of datasets (where the ref_name is pulled from dataset.filename) as before, or a dict mapping the ref_name to the dataset, which becomes the preferred ref_name in the run if it's included.

Testing

>>> import nominal as nm
>>> from nominal import Dataset, Run
>>> dataset = Dataset(nm.data.penguins(), "penguins.csv")
>>> r = Run(datasets=[dataset])
>>> r.upload()

Link to Run:
https://app-staging.gov.nominal.io/runs/
<Response [200]>
>>> r = Run(datasets={"test-ref-name": dataset})
>>> r.upload()

Link to Run:
https://app-staging.gov.nominal.io/runs/
<Response [200]>

As expected, the first run uploaded has the dataset ref_name "penguins.csv", the dataset filename:

and the second run uploaded has the dataset ref_name "test-ref-name":