mv Entity files dicts-to-objects code into function

The code takes the list of file info dicts from entity.json,
copies it, and then replaces it with a list of file objects.
This function will also be used by the remove-duplicates function.
remove duplicate files from Entity on user request

- Functions for detecting duplicate files and for removing them.
- View code for informing the user about duplicates, asking for
  confirmation, and removing them.