Add DQM modules for single lepton+HT SUSY triggers

PR adds DQM modules for single lepton+HT SUSY triggers not included in #6255:
HLT_Ele15_IsoVVVL_BTagtop8CSV07_PFHT400
HLT_Ele15_IsoVVVL_PFHT400_PFMET70
HLT_Ele15_IsoVVVL_PFHT600
HLT_Ele15_PFHT300
HLT_Mu15_IsoVVVL_BTagCSV07_PFHT400
HLT_Mu15_IsoVVVL_PFHT400_PFMET70
HLT_Mu15_IsoVVVL_PFHT600
HLT_Mu15_PFHT300

Forward port of #6520 to CMSSW_7_4_X. Merging directly since the latter is fully signed.