Previously, contact shares would be displayed as "Media Message". Now
it'll show the same as it does in a notification, namely
"{contact-emoji} {contact-name}".
When you share a vCard from an external app (like the Contacts app) into
Signal, we'll now convert it to a pretty Shared Contact message and
allow you to choose which fields of the contact you wish to send.
The "contact" option in the attachments tray now brings you through an
optimized contact sharing flow, allowing you to select specific fields
to share. The contact is then presented as a special message type,
allowing you to interact with the card to add the contact to your system
contacts, invite them to signal, initiate a signal message, etc.
