Create a WikiLambda API that performs validation on a given ZObject.
Need to decide on how validation works. I see two main models:
- it returns a list of Z5/Error ZObjects. If the list is empty, validation passed. Otherwise, the list contains as many independent errors as possible.
- return the ZObject itself unchanged if valid, otherwise return an Z5/Error ZObject (we should have an error type that says "multiple errors, which are")