Experimental split sts geometry

The sts which is split down the middle into a left and right side.
This geometry is placed in the same volume ordering to pervent need
for code changes.

setup/setup_sis18_hadron2.C

+/** ROOT macro to define the CBM setup sis18_hadron
+ **
+ ** Contains: STS + TOF
+ **
+ ** @author Volker Friese <v.friese@gsi.de>
+ ** @author David Emschermann <d.emschermann@gsi.de>
+ ** @date   5 February 2016
+ **
+ **/
+
+// 2022-03-24 - DE - Prepare SIS18 setup: 5 downstream layers of STS + TOF @ 3.2 m
+// 2022-02-17 - EC - Places PSD in its parking position
+// 2021-12-15 - EC - Candidate DEC21 geometries for testing.
+// 2020-04-23 - FU - Use exported TOF geometry v16d (same as v16c but
+//                   different file format
+// 2017-11-24 - VF - New default v16g for STS (unit-based)
+// 2017-11-20 - DE - use TRD v17n as new default
+// 2017-05-22 - DE - use TRD v17c as new default
+// 2016-06-27 - DE - use STS v16x as new default, see issue #647
+// 2016-05-19 - VF - Add platform module
+// 2016-02-25 - DE - use STS v16c as new default
+// 2016-02-05 - VF - Replaces former sis100_hadron_setup.C,
+//                   now using the CbmSetup class.
+// 2015-12-11 - DE - use STS v15c as new default
+// 2015-07-20 - FU - magnet v15a is v12b with correct keeping volume material
+// 2015-07-20 - FU - add material budget files
+// 2015-03-13 - DE - use STS v13y with correct ladder orientation as new default
+// 2015-01-29 - DE - use chopped PIPE v14q as default
+// 2015-01-19 - DE - use TRD v15a as new default
+// 2014-06-30 - DE - make TRD v14a the new default
+// 2014-06-25 - DE - define digi files through tags for STS, TRD and TOF
+// 2013-11-05 - DE - switch to trd_v13p geometry
+// 2013-10-11 - DE - add empty string defining the platform
+// 2013-10-07 - DE - pipe_v13c.geo fixes overlap with TOF, fills RICH section
+// 2013-11-04 - VF - make STS v15b the new default
+
+
+void setup_sis18_hadron2()
+{
+
+  // -----  Geometry Tags  --------------------------------------------------
+  TString magnetGeoTag    = "v21a";
+  TString pipeGeoTag      = "v21d";
+  TString stsGeoTag       = "v21k";
+  TString tofGeoTag       = "v21b_1h_sis18";
+  TString platGeoTag      = "v22a";
+  // ------------------------------------------------------------------------
+
+
+  // -----  Magnetic field  -------------------------------------------------
+  TString fieldTag      = "v18a";
+  Double_t fieldZ       =  0.;            // field centre z position
+  Double_t fieldScale   =  0.35.;            // field scaling factor
+  // ------------------------------------------------------------------------
+
+  // -----  Create setup  ---------------------------------------------------
+  CbmSetup* setup = CbmSetup::Instance();
+  if ( ! setup->IsEmpty() ) {
+  	std::cout << "-W- setup_sis18_hadron: overwriting existing setup"
+  			      << setup->GetTitle() << std::endl;
+  	setup->Clear();
+  }
+  setup->SetTitle("SIS18 - Hadron Setup");
+  setup->SetModule(ECbmModuleId::kMagnet, magnetGeoTag);
+  setup->SetModule(ECbmModuleId::kPipe, pipeGeoTag);
+  setup->SetModule(ECbmModuleId::kSts, stsGeoTag);
+  setup->SetModule(ECbmModuleId::kTof, tofGeoTag);
+  setup->SetModule(ECbmModuleId::kPlatform, platGeoTag);
+  setup->SetField(fieldTag, fieldScale, 0., 0., fieldZ);
+  // ------------------------------------------------------------------------
+
+  // -----   Screen output   ------------------------------------------------
+  setup->Print();
+  // ------------------------------------------------------------------------
+
+}