Remove fullstop automatically when it finds the same description

This idea is to save time clicking to remove exactly the same description that already has been approved to be removed. For example:

- "Grade II listed building in Powys." [action: **Remove full stop**]
But the script can save time if the action would be:
- "Grade II listed building in Powys." [action: **Remove identical full stops automatically**]
It means that if the script find again "Grade II listed building in Powys.", it isn't going to ask for the action to perform, neither quit or skip, it would be removed instantly.

This new action would save time and improve the efficiency of the script, but it couldn't be used with all the descriptions, because it would overload the system for nothing. It has to be used for a specific kind of descriptions, like the one mentioned.

### How would it work

The script would have a new action: Remove identical full stops automatically. This new action will add the description to a CSV, previously created and loaded with only one column named `sentence`. But, before to add it the script has to confirm if the description is already in the CSV: if it is in the CSV, it isn't added, if it isn't, it is added.

This descriptions saved in this CSV would be useful for the next times the script would be run, because the script would read this document, which would storage the old descriptions marked to find and remove automatically and the new ones.

### Tasks

- [x] Development of the action and the requirements to work.
- [x] System to avoid to add duplicated descriptions in the CSV.
- [x] Make easy to generate the CSV file in order to follow the commented in #5.
- [ ] Test several times.

Review the existing action implementation and the CSV generation/loading flow described in issue #10. Run the script repeatedly with identical descriptions and verify that approved descriptions are removed automatically, duplicates are not added, and saved entries work on later runs. The remaining task is to complete and document these repeated tests.

Written by the indexing model from the issue text.