Should `Controller` be exclusive to `Segment`?

I wonder whether we could have a controller that is attached to more than one segment: is-exclusive="yes" on this line is implying that to be the case, but I think that could be relaxed.

This leads to code that doesn't look too good in daqsystemtest here and here, which are effectively the same controller.

Of course, doing that would allow you to use the same controller for all the segments (for example you wouldn't need df-controller, ru-controller, ... to be defined, just have one), which of course wouldn't work, unless we name the controller after their segment they control (relevant code in the run control: here for the place where we use names like root-controllerto grab the controller configuration and here where the name of the controller is planted into the command line).

Start at schema/confmodel/dunedaq.schema.xml around line 354, then inspect the two daqsystemtest example-configs.data.xml references and the shared controller in ccm.data.xml. Read the linked drunc controller interface and oks_parser.py locations to understand how controller names select configuration. Done requires a decided design for shared controllers and coordinated updates across these configurations and consumers; no tests are named.