Port to zbus

I created the MR early since there are some code changes that I am not sure of.

Blockers:

• Figure out the API for zbus and upstream it
  • Issue: https://github.com/dbus2/zbus/issues/326 (Closed)
  • PR: https://github.com/dbus2/zbus/pull/370 (Merged)
• Improve variant display
  • Issue: https://github.com/dbus2/zbus/issues/366 (Closed)
  • PR: https://github.com/dbus2/zbus/pull/379 (Merged)