Offscreen on sky footprint selection

[bmatthieu3]

Intersection between polygons is currently done like that (in javascript):

• a bounding box of the selection is done
• this selection bbox is tested for intersection of all the footprints

This does not work well for polygonal footprints, I suspect there is a bug to fix

First step would be to fix it in JS.

The next step would be to use https://github.com/cds-astro/cds-skyregion-rust for representing the shapes (on the rust side) and use it to do the intersection. This will also allow to compute sky intersection directly, it is currently not possible to retrieve the shapes intersecting a list of radec vertices on the sky because JS intersection are done on the screen.
This would require more work because I have to bind the shapes from JS to rust first.

[bmatthieu3]

@tomdonaldson - I did a fix on the selection of footprints with a rectangle/circle/poly, it behaves more normal as of now. It will appear on the next beta/release.

I also updated that issue to fit something you asked some time ago i.e. I remember that you wanted a way to get intersections on the sky as well (a method that returns which footprints are intersecting a polygon on the sky, not in the screen).