Function interior_point 

pub fn interior_point(geometry: &Geometry<f64>) -> Option<Coord<f64>>

Computes an interior point of the given geometry.

For different geometry dimensions:

• Area (Polygon/MultiPolygon): uses scanline algorithm
• Line (LineString/MultiLineString): finds vertex closest to centroid
• Point (Point/MultiPoint): finds point closest to centroid

For GeometryCollections, uses the highest-dimension component.

Returns None if the geometry is empty.