enh: improve occ file:transfer-ownership logging

[grnd-alt]

When using occ file:transfer-ownership, we had issues reported that not all files where transferred when using s3 buckets as file storage.

This PR improves the logging of the occ command to inform users when not all files are transferred.

[juliusknorr]

@grnd-alt Please assign labels on new prs and provide a meaninful description, especially for reviewers that have not been involved before this will speed up review as it is easier to understand the context

[juliusknorr]

Also conventional commit message should be feat not fix I'd say

[come-nc]

The current wording is not clear enough I think.

[come-nc]

I’m afraid of the performance impact of this.
For source size it may have it in cache, but for the destination user it will force a full scan, no?
Also, the source size may not be perfectly up to date in the cache and this will result in a false-positive?