Add DBus API for adding contact with preset properties

The API takes an array of (key, value) pairs.

Supported keys:

These can be specified multiple times:
  "email-addresses", "notes", "phone-numbers"

Only the last will be stored (because this properies are unique):
"alias", "full-name", "nickname"

Not all properites are supported for now because they can't be easily
set via DBus because they arn't a string

Example DBus usage:

gdbus call --session --dest org.gnome.Contacts --object-path  /org/gnome/Contacts --method org.gtk.Actions.Activate 'new-contact-data' '[<[("email-addresses", "julian@sparber.net"), ("phone-numbers", "+39333333"), ("email-addresses", "secondo@example.com")]>]' '{}'
2 jobs for add-contacts in 6 minutes and 17 seconds
latest
Status Job ID Name Coverage
  Review
passed #1172264
style-check

00:00:17

 
  Test
passed #1172265
flatpak
flatpak

00:05:59