qcscine/molassembler: Release 1.2.1

Abstract

Changes: Include the shape position groups into the serialization to ensure the correct reconstruction of site to vertex maps. This should make the molecule serialization and deserialization more consistent (and less error prone). DirectedConformerGenerator::binMidpointIntegers deprecated because it returns dihedral angles that are defined differently from DirectedConformerGenerator::Relabeler::add.