Create 'orbits' property in OrbitPlotter
Create 'orbits' property in OrbitPlotter

Also some mypy fixes

newlawrence/poliastro,poliastro/poliastro,anhiga/poliastro,newlawrence/poliastro,newlawrence/poliastro,Juanlu001/poliastro,anhiga/poliastro,Juanlu001/poliastro,Juanlu001/poliastro,anhiga/poliastro