Use explicit column names for union select statements

What does this MR do and why?

Here we change the set operator so always explicitly use the column names in select.

I have based this on !121698 (closed) to detect any select * statements in union (or any set operators) just in case any of them is missed by the set operator changes.

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #412824 (closed)