revisit the FASP simulator software

Update for the FASP simulator software

• fix confusion wrt usage of DAQ time [clk] and physics time [ns] in digi time definition.
• add system time offset to equilibrate wrt to reference detectors (T0, ToF).
• use data from mCBM22 to calibrate TRD2D time resolution and offset for both EbyE and TB modes
• fix flushing of data during TB sumulations (still to be optimized wrt the event rate)

Time based simulations for mCBM22

• setup = setup_mcbm_beam_2022_05_23_nickel.C
• event rate = 1.e5 Hz
• time slice length = 1.4e5 ns

Event by event simulations (same as above)

Example of FASP simulator going from:

• physics energy deposits / read-out area pad (markers)
• amplifier shaper (black)
• analogue output (red) *) the calibration and mappings from the actual data taking are used to generate the detector response.