ATR-19303: Example to configure simple example electron chain

Trigger/TriggerCommon/TriggerJobOpts/python/TriggerConfig.py

.../TriggerMenuMT/python/HLTMenuConfig/Egamma/ElectronDef.py

.../python/HLTMenuConfig/Egamma/generateElectronChainDefs.py

...enuMT/python/HLTMenuConfig/Menu/ChainConfigurationBase.py

...TriggerMenuMT/python/HLTMenuConfig/Menu/GenerateMenuMT.py

...rCommon/TriggerMenuMT/python/HLTMenuConfig/Menu/LS2_v1.py

...TriggerMenuMT/python/HLTMenuConfig/Menu/MenuComponents.py

...iggerMenuMT/python/HLTMenuConfig/Menu/TriggerConfigHLT.py

...ger/TriggerCommon/TriggerMenuMT/scripts/generateMenuMT.py

Trigger/TriggerCommon/TriggerMenuMT/scripts/test_HLTmenu.sh

Trigger/TriggerCommon/TriggerMenuMT/share/generateMT.py