Add Trd2d for event building

The MR is aimed at fixing a problem appeared for the Trd2d with the advent of mCBM 2021 data taking but affecting the whole TRD group on the longer run; namely the accommodation of 2 pad-plane pick-up electrode topologies (rectangular and triangular) operated by 2 types of FEEs (SPADIC and FASP). Since this is a particularity of only the TRD system the modifications are somehow wider affecting tangentially also parts of the general steering code.

Basically the MR aims at the following :

• Extend functionality of BuildRawEvents (Algo/Task) to incorporate also data from Trd2d
• Add data descriptors for Trd2d in the CbmDefs
• add a proposal for a steering script for event building for mcbm 2021

reco/eventbuilder/digis/CbmAlgoBuildRawEvents.h

@@ -260,7 +260,6 @@ private:
     RawEventBuilderDetector(ECbmModuleId::kSts, ECbmDataType::kStsDigi, "kSts"),
     RawEventBuilderDetector(ECbmModuleId::kMuch, ECbmDataType::kMuchDigi, "kMuch"),
     RawEventBuilderDetector(ECbmModuleId::kTrd, ECbmDataType::kTrdDigi, "kTrd"),
-    RawEventBuilderDetector(ECbmModuleId::kTrd2d, ECbmDataType::kTrd2dDigi, "kTrd2d"),
     RawEventBuilderDetector(ECbmModuleId::kTof, ECbmDataType::kTofDigi, "kTof"),
     RawEventBuilderDetector(ECbmModuleId::kRich, ECbmDataType::kRichDigi, "kRich"),
     RawEventBuilderDetector(ECbmModuleId::kPsd, ECbmDataType::kPsdDigi, "kPsd")};