Simplify error messages against intersections of weak types

I spoke a bit with @sandersn about ways we can tackle the type madness issue (#14662). I noted that JSX scenarios are much more broadly applicable right now and are pretty prevalent given the sorts of type arithmetic we see a lot of in the React community. 😃

Problem: JSX optional attributes make errors too hard to read

interface FooProps {
    name: string;
    age: number;
}

class Foo extends React.Component<FooProps> {
    constructor(props: FooProps) {
        super(props)
    }
    render() {
        const {name, age} = this.props;
        return <div>I'm {name} and am {age} years old</div>;
    }
}

// Type '{ blah: number; }' is not assignable to type 'IntrinsicAttributes & IntrinsicClassAttributes<Foo> & Readonly<{ children?: ReactNode; }> & Reado...'.
//   Type '{ blah: number; }' is not assignable to type 'Readonly<FooProps>'.
//     Property 'name' is missing in type '{ blah: number; }'.
<Foo blah={10} />;

Proposal

When doing relation checks against an intersection target, if a check fails, see if relating against the same type with weak types removed would result in the same outcome. If so, use that comparison when elaborating types.

The great part is that this actually solves a broader set of problems than just JSX.

Comienza con la reproducción de JSX en el issue y sigue las comprobaciones de relación de tipos para un objetivo de intersección con tipos débiles. Compara el diagnóstico actual con la comparación propuesta que elimina los tipos débiles; se considera terminado cuando el error de JSX se simplifica sin cambiar el resultado de la relación, mientras se siguen cubriendo los casos afectados más amplios.