dRICH: miscellaneous cleanup

• several minor changes for cleanup and to help with IRT integration (and to keep !31 (merged) minimal)
• some things are moved around, to allow for easier IRT geometry integration
• Transform3Ds for placement are reformatted, so clang-format won't mess them up
• the sensor ID imodsec is built using the readout decoder; we need this number for IRT, and possibly other algos; probably could decode cellID from the Juggler side, but having it done this way was useful for standalone IRT tests (that bypassed Juggler)