Currently X ≈ Y crashes for some set types (of the same type) that have fields for which we do not have _isapprox methods, such as Vector{HalfSpace} in the HPolygon/HPolytope etc. types. For these set types we need a specific method for ≈. Finally remove the TODO introduced in #2569.

x-ref: #1916, #2370

This list might be incomplete:

• HPolygon, HPolygonOpt, HPolytope, HPolyhedron
• VPolygon, VPolytope
• probably all lazy set types