Add contacts-reading plugin (KDE side)

Summary:
Add a plugin to KDE Connect which supports exporting the Android contacts databases to vcards on the desktop

When the devices are connected, the plugin sends a request for all timestamps and IDs

When a packet with timestamps and IDs is received, it verifies it has vcards for each ID and that the timestamps match and deletes any vcards for IDs which were not reported. It then sends a request for all vcards which were missing or need updating

When a packet with vcards is received they are unconditionally written to disk, possibly overwriting existing vcards

Provides one dbus method: contacts/synchronizeRemoteWithLocal which triggers the request for all timestamps and IDs

BUG: 367999

Test Plan:
Connect the device to the desktop and verify that vcards are created in QStandardPaths::GenericDataLocation / kpeoplevcard". On my system this is ~/.local/share/kpeoplevcard

Create a dummy contact on the device and verify it is synchronized (Currently not automatic, have to disconnect and reconnect or use dbus)

Modify the dummy contact and verify the modifications are synchronized (Currently not automatic, have to disconnect and reconnect or use dbus)

Delete the dummy contact and verify the deletion is synchronized (Currently not automatic, have to disconnect and reconnect or use dbus)

Reviewers: KDE Connect, apol

Reviewed By: KDE Connect, apol

Subscribers: mtijink, KDE Connect, apol

Tags: KDE Connect

Maniphest Tasks: T8283

Differential Revision: https://phabricator.kde.org/D9691