arrow

GH-39720: [Swift] Switch reader to use arrow field instead of proto for building arrays (#39721)

This PR updates the ArrowReaderHelper to use an ArrowField object for building an Array instead of a protobuf field obj.  This removes leveraging protobuf from building out the Arrays and makes the code easier to reuse (like for the C Data Interface)
* Closes: #39720

Authored-by: Alva Bandy <abandy@live.com>
Signed-off-by: Sutou Kouhei <kou@clear-code.com>