Introduce T-ZERO digitizer (Refs #2630)

Introduce a digitizer for the t-zero detector with a simple, parameterised implementation along with a digi data class. Refs #2630.

core/data/global/CbmBmonDigi.cxx

+/* Copyright (C) 2022 GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt
+   SPDX-License-Identifier: GPL-3.0-only
+   Authors: Volker Friese [committer] */
+
+#include "CbmBmonDigi.h"