Refactor HLT1.py to avoid code duplication and ensure changes to common code are taken into account when moving from pp to e.g. PbPb

During PbPb data taking, issues were observed due to a prescale on the material vertices maker (see !2244 (merged)) not correctly ported to PbPb.

This issue requires to refactor HLT1.py decoupling from it a HLT1_common.py, in such a way that changes to technical lines are automatically included when moving from pp to PbPb data.

cc @msaur