The tracks output file name update

Previously, the tracks file name was set to Tracks_data.h5. It was the source of the program crash. If one keeps the tracks file opened in the Gmex and tries to simulate it with the tracks plugin, the program will crash with the following message:

HDF5-DIAG: Error detected in HDF5 (1.10.4) thread 139746049515136:
  #000: ../../../src/H5F.c line 444 in H5Fcreate(): unable to create file
    major: File accessibilty

    minor: Unable to open file
  #001: ../../../src/H5Fint.c line 1364 in H5F__create(): unable to open file
    major: File accessibilty
    minor: Unable to open file
  #002: ../../../src/H5Fint.c line 1615 in H5F_open(): unable to lock the file
    major: File accessibilty
    minor: Unable to open file
  #003: ../../../src/H5FD.c line 1640 in H5FD_lock(): driver lock request failed
    major: Virtual File Layer
    minor: Can't update object
  #004: ../../../src/H5FDsec2.c line 941 in H5FD_sec2_lock(): unable to lock file, errno = 11, error message = 'Resource temporarily unavailable'
    major: File accessibilty
    minor: Bad file ID accessed

terminate called after throwing an instance of 'H5::FileIException'

The reason for the crash is that FullSimLight tries to rewrite the Tracks_data.h5 file while it stays open in the Gmex.

In the updated implementation, if the file with the name Tracks_data.h5 already exists, the file with a different name will be created as an output of the simulation. So, the problem described above must not appear.