Function importer::utils::download_kml

pub async fn download_kml(
    output: String, 
    url: &str, 
    bounds: &GPSBounds, 
    require_all_pts_in_bounds: bool, 
    timer: &mut Timer<'_>
)

If the output file doesn't already exist, downloads the URL into that location. Clips .kml files and converts to a .bin.