💡 Feature Request: Provide more robust handling of `anyOf(string, object)` scenarios

Related to issues discovered during work on these PRs:

- #251
- #246

We currently fall back to string type as a failsafe whenever we get a type we can't type properly. For cases where the field is defined as `anyOf(string, object)`, aka `type = ["string", "object"]` or `type = ["null", "string", object"]`, we are considering changing the behavior so that the value would be stored in a JSON-like field, such as `JSON` or `VARIANT`.

These JSON-like types are capable of holding "bare" string values as well as other variant data.