SLB Nov Hackathon: Enable fiducial cut

Enable the fiducial cut on isolation pions for SLB modes by default.

This is about 99.7% efficient on signal pions (truly matching with an excited particle) and about 85% background efficient. It reduces the total number of combinations we need to make, should also increase throughput slightly, but that needs to be tested.

I also make the application of the fiducial cut optional for the end user (enabled by default).