[WIP][FEATURE] additional fields for contact (form of address, salutation, disabled)


__Tasks:__

- [ ] adjust api
- [ ] test coverage
- [ ] extend configuration for keys <-> translation key and make it available to the via api
- [ ] integrate fields in form
- [ ] gather feedback for my changes

__Informations:__

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| Tests pass?   | yes
| Fixed tickets | [none]
| Doc           | none