DecReports written as if no lines are configured

@dcraik noticed in data from the VdM scan that the DecReport encoding key sometimes appears at the wrong location in the RawBank. After some investigation, we found that only 3 words were written to the DecReport body for each event, consistent with 0 trigger lines. However, the data for the configured lines are still present in the Allen DecReport buffer, so random chunks of the DecReports are written to the output RawBank. Our best guess is that the DecReports created in Allen were correct, but the output was prepared as if 0 lines were configured.

The number of lines for the OutputProvider is set here: https://gitlab.cern.ch/lhcb/Allen/-/blob/master/main/src/Provider.cpp#L279, so this could have something to do with the sequence json file. Maybe @dcampora has some ideas.

FYI @raaij