memoized_path_copy helper to complement @memoize_path

In the light of https://github.com/dandi/dandi-cli/issues/848 discussion to allow for more efficient caching of digests, I wondered if it would be feasible to provide something like `memoized_path_copy` which would copy all (?) memoized invocations for a specific decorated function as they were invoked for another "new" path.

ATM, looking at the code, and since we rely on joblib memoization and otherwise do not track what specific parametrizations of the function were used, I really do not see how we could even do that. But may be you @jwodder see some way to provide such functionality?