* Raise a specific class error instead of string literal when the type returned doesn't match the type expected. Allows for drivers to catch the specific error.
* Add ResultSet#next_column_index
* Add shared specs for next_column_index
* Add properties to ColumnTypeMismatchError
* Add shared specs for ColumnTypeMismatchError
* Fix specs
Co-authored-by: Brian J. Cardiff <bcardiff@gmail.com>