Improved MM L1 Simulation workflow

Simplified workflow by reducing the number of involved objects, more specifically:

• MMT_Diamond class:

  • Removed calls to Get_MMDetector(...) and GetReadoutParameters() and related include declarations
  • Removed micromegas_t filling procedure
  • Parameters taken from MMT_struct class with dedicated get functions, as the aforementioned calls were already there

• MMT_Road class:

  • Removed micromegas_t struct template
  • Removed unused class members
  • Changed constructor accordingly

• MMT_Hit class:

  • Added default destructor, as it was missing
  • Removed 1st parameter from constructor, as another one was enough to retrieve it

• MMTriggerTool class:

  • Retrieve slope vector when running in ST only

As this MR involves the removal of some redundant elements, some small improvements may be expected from the ATR-25528 point of view

./cc @vadamico