Simong 128 fix qhda reports

Context

• Project README: https://gitlab.cern.ch/LHCData/lhc-sm-api
• Story reminder:
  Plots for Quench Heater Discharge Analysis on FPA and HWC are differents https://its.cern.ch/jira/browse/SIGMON-128
• Task details:

• Understand why the plots on FPA are not correct and not aligned with the HWC.

linked MR: lhc-sm-hwc!21 (merged)

What was done

• keypoints of the implementation

• Update on the Plotting method on the QuenchHeaterVoltageCurrentAnalysis.py for plotting the analysis signals.
• Update the evaluation of the indexes of the current and voltage (same for references.)

QA

• code was unit tested

Review objectives

• assessment of code functionality
• assessment of code quality
• identifying potential refactorings / logic common to other projects
• knowledge sharing