add background electron triggers for Run3 to EGAM derivations

Add to Run3 background electron trigger list 2 more triggers 'HLT_e5_nopid_L1EM3', 'HLT_e5_etcut_L1EM3', (see comment from yesterday in https://its.cern.ch/jira/browse/ATLEGAMDPD-206?focusedCommentId=4618353&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-4618353)

(and reorder other triggers in same list by electron/photon energy)