REF: share code between pd.array and Series constructor
I've noticed a couple of places in the code where we do runtime imports of Series just to do `values = Series(values)._values`.  It would be nice to avoid that.

This probably also means moving parts of internals.construction to somewhere like `arrays.array_`.  In particular I think this would require moving sanitize_array and _try_cast.  Since sanitize_array is imported by other modules, this would be nice to have non-internals anyway.

Finally there are some functions in dtype.cast that might make more sense alongside sanitize_array, e.g. construct_1d_object_array_from_listlike