remove cloning from geo iterators in trait

[kylebarron]

• this should be copied into geo as well
• I wonder if there's a perf improvement from the removed cloning
• It would be nice to make a quick bench before merging

[kylebarron]

Turned out this was super simple to implement, I just had to remove Iter's dependency on Self::ItemType. cc @JosiahParry since this can simplify your code here https://github.com/JosiahParry/serde_esri/blob/1f7f70e086463079bc2d99b925580e052b7382be/src/geoarrow_compat.rs#L56. I don't think you need a separate iterator struct unless you want to

[kylebarron]

omg yessssssss. This branch compared to main 🚀 cc @JosiahParry

convert Vec<geo::Polygon> to PolygonArray
                        time:   [31.564 µs 31.608 µs 31.661 µs]
                        change: [-52.414% -52.271% -52.131%] (p = 0.00 < 0.05)
                        Performance has improved.

[JosiahParry]

SHEEEEEESSH!