This makes it easier to spot syntax errors when editing the
class reference. The schema is referenced locally so validation
can still work offline.
Each class XML's schema conformance is also checked on GitHub Actions.
Same as what is already done for shape queries, applied to point and ray
queries. Easier to document and more flexible to add more parameters.
Also expose intersect_point method to script in 3D.
Remove intersect_point_on_canvas in 2D, replaced with a parameter.
