Add osxphotos dup-sync command

[RhetTbull]

osxphotos dup-sync would find duplicates and sync all metadata such as folders/albums, favorite, keywords between them all. Optionally add a --signature which allows a template to define "what is a duplicate" (otherwise use fingerprint). Add options for adding either oldest or newest to an album (e.g. "Keep") and others to another album, e.g. "Delete")