Adding noOnlineMon flag to chain definitions to replace clean monitoring (ATR-19536)

To replace the "clean monitoring" (see ATR-19432, ATR-19536) in the menu for egamma & jets, a new string 'noOnlineMon' has been introduced to not write histograms online. This can be obtained via the chainDictionary that is passed to the HypoTools. An example of the usage is shown in TrigL2ElectronHypoTool.py This MR also removes to MEOW print statements pointed out by Frank in !21882 (merged). It is based on the branch in the MR !21882 (merged) as this was adding fixes for the newly introduced pyflake test.