Implemented changes discussed in ADHI-4728 required to support holding trigger during P1 online operation. When reading new events is paused (i.e. trigger is held), the online framework has to continue processing events it already has "on the fly", finish the processing, send the outputs, and keep waiting until the pause ends.
On the DCM (TDAQ) side a timeout for "getNext" call will be implemented and the DataCollector implementation will return
NO_EVENT on timeout. This should be interpreted by the HLT as "trigger on hold".