cache migrate: add an option to update dvc files

[dberenbaum]

dvc cache migrate will update the cache but not the .dvc and dvc.lock files. Users can manually drop these all themselves and then add them back, but it's tedious and error-prone. Can dvc cache migrate (possibly with some flag like --dvc-files) do this automatically?

[dberenbaum]

Related:

• dvc repro --dry --allow-missing: fails on missing data #9818
• Force DVC to Reference 3.0 cache locations #9930

[dberenbaum]

Initially the idea was raised to make this part of dvc commit -f, but this could be problematic since dvc commit -f doesn't touch unchanged files, so it makes sense more as part of cache migrate.