Introduce filters on HLT1 lines for D2HHGamma

Partially addresses #854 (closed) by requiring these lines to only run on events fired by the one or two-track MVA triggers in HLT1.

Tested with https://gitlab.cern.ch/-/snippets/3269 and reduces the bandwidth of these lines by 1/3, saving around 50 MB/s.

@mvesteri @cagapopo @tpajero @fbetti @cacochat @aanelli @lpica