output-management-v1: add head identifying events
Created by: subdiff
The following information through separate events are added:
- make
- model
- serial_number
This should allow clients to identify a display over different sessions and load configuration data back.
A note is added that the description should be preferred when representing a display in UI to users but as a short form for example the model could be used in this case of course too.
Related: https://github.com/swaywm/wlroots/pull/2392
Closes #68 (closed)