refactoring: use library class method for constructing Polygon from bbox
refactoring: use library class method for constructing Polygon from bbox

geometalab/osmaxx,geometalab/drf-utm-zone-info,geometalab/osmaxx-frontend,geometalab/osmaxx,geometalab/osmaxx,geometalab/osmaxx-frontend,geometalab/drf-utm-zone-info,geometalab/osmaxx,geometalab/osmaxx-frontend,geometalab/osmaxx-frontend