Updated trigger chain names in TrigEgammaMonitoring configuration

This is to update trigger chain names in TrigEgammaMonitCategory and in TrigEgammaMonitoringMTConfig to fix a typo on name of primary electron chains for legacy and add the corresponding in MT monitoring to be shown. This is a follow up fix for validation tickets like ATLASDQ-758 and ATLASDQ-785

Mentioning also @temoskal @safarzad dbakshig @jodafons and @eegidiop