refactoring: move extra context data in mixin
refactoring: move extra context data in mixin

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