[Enhancement] implement "defineProperty" trap as well

[Andreas Rozek]

Object.defineProperty is a commonly used approach to define new object properties - internally, Reflect.set(...) will invoke Object.defineProperty anyway whenever a new property is to be set.

For that reason, it is a good idea to implement the "defineProperty" trap in order to catch all situations, where new properties are defined.

The required changes should be trivial (see my own fork of your repository)

[Luis Herranz]

I've been thinking about this and for the moment I'm not going to add a defineProperty trap. I'm not sure what are the use cases or even if using defineProperty to access the target is actually useful, and I wouldn't like to increase the bundle size unnecessarily.

I'd be happy to review this in the future if there are strong cases to support it, though!