CellUnion's raw=True normalises while it should not

[calestyo]

When creating a CellUnion with the default of raw=True, the cells get normalised, while for the CPP library it's just the other way round:
https://s2sphere.readthedocs.io/en/latest/cpp.html#_CPPv211S2CellUnion

void InitRaw(vector const &cell_ids)

Like Init(), but does not call Normalize(). The cell unionmust* be normalized before doing any calculations with it, so it is the caller’s responsibility to make sure that the input is normalized. This method is useful when converting cell unions to another representation and back. These methods may be called multiple times.