DM-38409: Remove support for int dataset IDs in Butler.transfer_from

[timj]

This significantly cleans up the code since there is no longer a need to collect the source and target refs separately and make Datastore.transfer_from have to keep track of them. With UUIDs the source ref and the target ref are the same.

Checklist

• ran Jenkins
• added a release note for user-visible changes to doc/changes

[codecov]

Codecov Report

Patch coverage: 92.85% and no project coverage change.

Comparison is base (a10d057) 85.58% compared to head (fb546f7) 85.58%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #807   +/-   ##
=======================================
  Coverage   85.58%   85.58%           
=======================================
  Files         266      266           
  Lines       35313    35293   -20     
  Branches     7435     7428    -7     
=======================================
- Hits        30222    30205   -17     
+ Misses       3759     3757    -2     
+ Partials     1332     1331    -1     

Impacted Files	Coverage Δ
python/lsst/daf/butler/core/datastore.py	81.04% <ø> (ø)
python/lsst/daf/butler/datastores/fileDatastore.py	81.06% <77.77%> (-0.06%)	⬇️
python/lsst/daf/butler/_butler.py	75.53% <100.00%> (-0.03%)	⬇️
...hon/lsst/daf/butler/datastores/chainedDatastore.py	87.92% <100.00%> (+<0.01%)	⬆️
tests/test_butler.py	97.44% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[andy-slac]

Looks good. Maybe add a news fragment?

[timj]

Maybe add a news fragment?

Yes. Meant to do that and then got distracted.