Send vCards

[zeitschlag]

• add support for sending vCards (depends on api: Add make_vcard() (#5203) deltachat-core-rust#5571)
• display in draft/staging

See #2167.

[r10s]

ftr, base class could GroupMembersViewController, which is also used for BlockedContactsViewController.

apart from the not-matching name, it offers search and probably everything we need for selecting a contact.

[Hocuri]

What's to do wrt the core API, I hope I didn't forget anything:

1. after click on "contact" in attachment menu, show a dialog to select one contact
2. Create a message with viewtype VCard

• Steps 3, 4 and 5 can be combined using api(jsonrpc): Add set_draft_vcard(.., msg_id, contacts) deltachat-core-rust#5677:
  3. get VCard including this contact by calling rpc.makeVcard
  4. save this VCard as temporary file
  5. attach this file to the message like a normal file attachement and set it as a draft. Alternatively, directly send it, staging as a draft can come later.