Is your feature request related to a problem? Please describe.
Often when doing a move what I want is to do trash if the two items are equal and rename_new if they aren't. I want to avoid adding a duplicate with a new name, but the destination directory isn't covered by the dedupe filter because it's not a source location.

Describe the solution you'd like
An on_conflict option that moves or copies the file only if there is not an equal file present. If speed demanded, filesize could be used as a heuristic instead of a full file sha1 or whatever. 90% of the time my files will have different sizes if they are unequal. Maybe a good name for this would be on_conflict: idempotent, cause multiple copies with the same file would have equal effect? Though I suppose technically a move would not be idempotent for the source directory...

Describe alternatives you've considered
I could choose rename_new, which would risk increasing bloat in my dest folder as new duplicate files come in. I could choose skip and risk missing the new files. I could somehow rig up my destination folder structure as a location and run a dedupe filter. But it's too big to realistically run a dedupe algorithm on all of it. There might be a way to break it into pieces and only execute the dedupe filter in a folder a file was added to.