Currently, an illegal target type (e.g., "minKey") results in a query failure, even if there is an "onError" value. This means that attempting to pass the return value of a $type expression as the "to" parameter can result in a failure.

With this change, an invalid target type will instead return the "onError" value when it is present. Note that a string or number that does not map to any type will still result in an error in all cases.