Added code for viewing vCard data within an unsupported account

The code now makes unsupported accounts appear and features which are
used for managing supported accounts are restricted with unsupported
accounts.

- New contacts can't be added.
- Contacts can be viewed but not edited in the contact editor
- Contacts cannot be deleted.
- Account settings cannot be edited.
- Account can still be deleted like supported accounts.
- Data can still be exported.