Add correct type safety to orderBy

[SH-Exact]

This PR completes the type safety of OrderBy by not taking the entity props as reference, but the properties of the *_Filter_Props types. Since the types can become pretty complex, which can break typescript, the syntax was changed from a . notation to a object definition as used for the include parameter, e.g.

wServices.article.some({
  orderBy: [
    {
      FIELD: {
        articleCategory: {
          name: true
        }
      }
    }
  ]
});

The README.md was adapted correspondingly.