`kafka_dae_control`: unset pause on runstart, or set it if doing an explicit `begin(paused=True)`

[Tom-Willemsen]

ISISComputingGroup/kafka_dae_control#67 (comment)

BEGINRUNEX wants to write to the paused veto bit, just before beginning a run:

• 0 if BEGINRUNEX got the value 0 which corresponds to a 'normal begin'. This ensures we don't accidentally start up a run in a paused state.
• 1 if BEGINRUNEX got the value 1 which corresponds to a 'paused begin'. This is equivalent to ICP's begin_paused functionality.