Fix ResultColumnMixin - add table reference for QueryResult

[griffio]

QueryResult.table was being hardcoded as null, add the table reference so that queryExposed() collection elements QueryResult.table can be used to determine the result column's table or table alias.

e.g Query Table reference could also be a TableAlias element.

SELECT *
FROM Orders o
JOIN OrderLines ol USING (order_id)

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• CHANGELOG.md's "Unreleased" section has been updated, if applicable.