WIP: Migration of T0 trigger monitoring code to athenaMT

This is a continuation of MR !22772 (closed)
I have started over with an updated Control/AthenaMonitoring package. The segfault persists though.
Very much WIP, do not merge yet.

This is being discussed in ATR-19677.

I have taken the files from the tutorial,
Control/AthenaMonitoring/AthenaMonitoring/ExampleMonitorAlgorithm.h
Control/AthenaMonitoring/python/ExampleMonitorAlgorithm.py
Control/AthenaMonitoring/share/ExampleMonitorAlgorithm_jobOptions.py
Control/AthenaMonitoring/src/ExampleMonitorAlgorithm.cxx

and moved them to the trigger package:
Trigger/TrigMonitoring/TrigEgammaMonitoring/TrigEgammaMonitoring/TrigEgammaMonitorAlgorithm.h
Trigger/TrigMonitoring/TrigEgammaMonitoring/python/TrigEgammaMonitorAlgorithm.py
Trigger/TrigMonitoring/TrigEgammaMonitoring/share/TrigEgammaMonitorAlgorithm_jobOptions.py
Trigger/TrigMonitoring/TrigEgammaMonitoring/src/TrigEgammaMonitorAlgorithm.cxx

where I just have made some minimal name changes to try to run it. The code compiles, but it seg faults when running (it creates an output root file, but does not fill it and the last line in the log file says "0 events processed".

Commands to run the code:

cd work/area/  
setupATLAS  
lsetup git  
git atlas init-workdir https://:@gitlab.cern.ch:8443/atlas/athena.git #first time only

cd athena  
git atlas addpkg TrigMonitoring # first time only    
git atlas addpkg AthenaMonitoring # first time only  

git fetch upstream  

git checkout -b master-my-branch-name upstream/master --no-track #first time only  

cd ..  
asetup master,latest,Athena  

mkdir run  
mkdir build  
cd build  
cmake -DATLAS_PACKAGE_FILTER_FILE=../package_filters.txt ../athena/Projects/WorkDir  
make -j8  
source x*/setup.sh  

Running trigger code:  
cd../run  
cp ../athena/Trigger/TrigMonitoring/TrigEgammaMonitoring/python/TrigEgammaMonitorAlgorithm.py .  
python TrigEgammaMonitorAlgorithm.py > mylog.txt &