`kafka_dae_control`: propose mechanism for reading/writing to arbitrary registers on individual detector boards

[Tom-Willemsen]

Come up with a generic interface to allow DSG to:

• Arbitrarily query and write to individual parameters on individual streaming boards
• Specify "the" set of parameters in some config file and be able to:
  • verify/compare these against the hardware state
  • bulk apply that set of parameters to the hardware
• Make sure all of the above is scriptable i.e. exposed as PVs