Draft: Throw error if MG job is trying to save gridpack

Changes introduced

Make logParser throw ERROR if madgraph is trying to output a gridpack. This is based on the presence of: 15:08:19 Py:MadGraphUtils INFO The grid_pack flag is set, so I am expecting to create a gridpack in this job

Tests

Can't test until I have a failing job. The one that I got from Ewelina seems to be correct (didn't see the above printout)

Issues resolved

Closes #143 (closed)