Feature request: better support for multiple AMSs

[chrmenne]

I have an X1C and had a script set up that when the printer switches to "RUNNING", it read the ams.tray_now value and used that to look up the AMSs tray_type. That way it could see what type of filament was used and control the chamber fan accordingly.

But now I got a second AMS, and both AMSs have trays 0 to 3. ams_tray_now" is still filled, but I don't know which AMS's tray is used and thus can't have a look at the spool anymore. Maybe there is a way to determine the id of the active AMS, or a way to give all trays a unique ID?