Add DecReportsMonitor to HLT2

The MR adds the monitoring of decisions to HLT2. The monitor cannot run in the output sequence as it would not see all events and only count the ones which were accepted. Therefore, the monitor is added after the trigger lines in a new main control flow node with the type NONLAZY_OR. To not use too much resources, the monitoring is only run on 10% of the events.

The current solution adds another layer of control flow nodes, we could make it simpler by not requiring to run on every event. In this case we would need an external normalization to monitor accept fractions.