Version contact fields.

[RokeJulianLockhart]

Is your feature request related to a problem? Please describe.

After moving my contact data from Git to NextCloud, I've lost all versioning.

Describe the solution you'd like

I'd like versioned contact fields. Precedence for similar functionality exists, like Bitwarden's versioned passwords.

Describe alternatives you've considered

Per-contact versioning, or transferring my contacts back to a Git repository.

Additional context

1. Although similar to Contact deletion management (trash bin, undo) #296 (comment), it's not identical, because that describes a restoration of an entire contact, whereas this requests the ability to revert to specific versions of contact fields.
2. An example "in the wild" of a user who would have benefitted from this feature in NextCloud is available at https://help.nextcloud.com/t/recover-lost-contacts-notes/56621/1?u=rokejulianlockhart#:~:text=Is%20there%20any%20way%20to%20retrieve%20this%20data%20from%20Nextcloud?%20Does%20Nextcloud%20have%20a%20log%20of%20contacts%E2%80%99%20fields?%20Or%20even%20a%20general%20Nextcloud%20log%20that%20might%20have%20this%20data%20stored%20somewhere.
3. A similar request for the aforementioned password manager exists at https://community.bitwarden.com/t/version-control-entire-items/15764/1?u=rokejulianlockhart#what-will-this-feature-do-differently-3:~:text=What%20will%20this%20feature%20do,am%20just%20considering%20the%20possibility.