Allow to check if a point is within ellipse on sphere

The use case from astronomical research team at CalTech: identify if the coordinates of the object (point) fall within the galaxy (boundaries are described as ellipse).
Currently ellipse is not supported natively, so the workaround is to store parameters of ellipses (not as geo data), use $geoWithin to perform search within much larger circle area and process data further in the code, which produces a lot of overhead.