Herwig7_i: Add new sampler options

We introduce a little changes for the Herwig7 Matchbox running mode. We need to add two new options to the sampler. We also add a way to run a debug mode. Since the precision needs to be very high for the normal running it takes a bit longer, if we now want to do debugging, we want to speed the process up, that's way in the debug mode, the error for the precision becomes a warning.

The changes have been tested with some Matchbox Job Options.