Migration of common silicon readout geometry code into new ReadoutGeometryBase package

This MR introduces changes following the discussion and needs detailed in ATLSWUPGR-92. It introduces a new package ReadoutGeometryBase and ports common functionality originally found in InDetReadoutGeometry which will also be used for the HGTD readout geometry. It touches many packages at a surface level due to the need to update all client packages of the classes which were moved to ReadoutGeometryBase.

Slides presenting this work have been shown in a recent HGTD 21.9 migration meeting here, in which representatives from upgrade software and upgrade physics were present.