Fix default monitoring if last alg in control flow does not have producer
Fix for a bug in the default monitoring as reported in https://indico.cern.ch/event/1265442/contributions/5314228/subcontributions/417935/attachments/2712620/4710610/DQreport_12_09_2023.pdf and elsewhere.
The issue was caused by a break
in the reverse loop of the control flow, which was triggered by a custom monitor as last algorithm in the control flow.
Also, the monitoring docs are updated and two unused functions in the commissioning settings were removed.
Supersedes !2633 (closed)