Port HGTD ReadoutGeometry from 21.9 to master
This MR is a follow-up to !43252 (merged) and continues the work of migrating the HGTD code developed in 21.9 into master. It adds the HGTD-specific readout geometry now that the identifiers are in place. HGTD_GeoModel
package to follow next.
Edited by David Richard Shope