Document that `from_arrow_array` uses `GeoArrowType::from_arrow_field` internally

[kylebarron]

See here, making from_arrow_field return Result<Option<GeoArrowType>> means that from_arrow_array must return Result<Option<Arc<dyn GeoArrowArray>>>.

But because from_arrow_field never returns Ok(None), so also from_arrow_field will never return Ok(None). So this feels like it needlessly infects all downstream code to require it to handle Option when it doesn't have to.

Alternatively, perhaps from_arrow_array should use GeoArrowType::from_extension_type internally.

Originally posted by @kylebarron in #1394 (comment)

geoarrow-rs/rust/geoarrow-array/src/array/mod.rs

Lines 46 to 71 in b771e88

	/// Construct a new [GeoArrowArray] from an Arrow [Array] and [Field].
	pub fn from_arrow_array(
	array: &dyn Array,
	field: &Field,
	) -> GeoArrowResult<Arc<dyn GeoArrowArray>> {
	use GeoArrowType::*;
	let result: Arc<dyn GeoArrowArray> = match GeoArrowType::from_arrow_field(field)? {
	Point(_) => Arc::new(PointArray::try_from((array, field))?),
	LineString(_) => Arc::new(LineStringArray::try_from((array, field))?),
	Polygon(_) => Arc::new(PolygonArray::try_from((array, field))?),
	MultiPoint(_) => Arc::new(MultiPointArray::try_from((array, field))?),
	MultiLineString(_) => Arc::new(MultiLineStringArray::try_from((array, field))?),
	MultiPolygon(_) => Arc::new(MultiPolygonArray::try_from((array, field))?),
	GeometryCollection(_) => Arc::new(GeometryCollectionArray::try_from((array, field))?),
	Rect(_) => Arc::new(RectArray::try_from((array, field))?),
	Geometry(_) => Arc::new(GeometryArray::try_from((array, field))?),
	Wkb(_) => Arc::new(WkbArray::try_from((array, field))?),
	LargeWkb(_) => Arc::new(LargeWkbArray::try_from((array, field))?),
	WkbView(_) => Arc::new(WkbViewArray::try_from((array, field))?),
	Wkt(_) => Arc::new(WktArray::try_from((array, field))?),
	LargeWkt(_) => Arc::new(LargeWktArray::try_from((array, field))?),
	WktView(_) => Arc::new(WktViewArray::try_from((array, field))?),
	};
	Ok(result)
	}

We should document that currently this applies data type coercion without requiring extension metadata to exist.