Add option to merge duplicates

[Rexadev]

Ask user for every contact merge

Situations

1. Same Name - Same Number
2. Same Name - Different Number
3. Different Name - Same Number (Ask user to Edit)
4. Same Name - Missing Detail (Like Email)

SimpleMobileTools/Simple-Contacts#944

Checklist

• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I have read the FAQ and my problem isn't listed.
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• This issue contains only one feature request.
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[N1N74]

Playnite is obviously a much more complicated setup to take inspiration from but UI like that for merging contacts would still be the best in this case. List differing fields, allow users to choose which to keep, use checkboxes where it can be used (like numbers and groups).

[anulin]

also after auto-merge you can only edit the just the first phone number and cannot see any other in edit menu

[AyushmaanAggarwal]

Another place to take inspiration from is nextcloud contacts ui which recently added a merge contacts featur(only between two contacts unfortunately)