Feature request: Metamodel verifier

[akphi]

As we are moving in the direction of simplifying metamodel (#263), we need to be able to verify at runtime that the metamodels that we constructed, are compliant with the model, i.e. checking to make sure required fields are set. This is good for development and we should cover this with tests ideally.

Implementation Plan

Right now, we don't have a good strategy yet to automate this, so we might need to manually define verifier for each metamodel like we do for hashCode - NOTE we can probably make use of hashCode to do this check (e.g. as we compute the hashCodes for fields, we can also verify that they are present).

As such, we have a few different strategies:

• Tinker with hashCode function to also do the verification.
• Poke into the prototype or something and inject fields we want to exclude (using something similar to serializer createDefaultSchema)

defineVerifiedProperty(Enumeration, {
  ignore: ["owner"], // use KeyOf<Enumeration> or something (like Jest Spy) to make sure `owner` actually is one of the fields of the object
  // or alternatively, we can do what `mobx makeObservable` does
});

[akphi]

In the spirit of #927 this is probably not a good idea. If we miss something, we would get a bug.