Change the setting of the TRestRun start and end times

[AlvaroEzq]

• Use always the FemDaq start time and end time to set the TRestRun time in the InitProcess(). If not, the start time was set when the process was runned and the end time from the modification time of the file.
• Add option to change this TRestRun start and end times to those of the first and last event. Normally, they should be very close but it could not be the case if there is some issues with the electronics. For example, when the TCM gets stuck in TREX-DM.