fix: add missing "comment" field to QueryExpressionMap.clone() method

[astritsh]

Closes: #7203

Description of change

Added missing "comment" filed to QueryExpressionMap.clone() method.
In my understanding, clone method should copy every field, including the "comment" one.
Seems that clone() method was not updated after adding "comment" field to QueryExpressionMap.
In my case I have used "comment" for something special and when calling getManyAndCount(), count query was missing the "comment".
Added a unit test to confirm that clone method copies comment as well.

Pull-Request Checklist

• [x ] Code is up-to-date with the master branch
• [ x] npm run lint passes with this change
• npm run test passes with this change
• [x ] This pull request links relevant issues as Fixes #7203
• [x ] There are new or updated unit tests validating the change
• Documentation has been updated to reflect this change
• [ x] The new commits follow conventions explained in CONTRIBUTING.md

[pleerock]

Thank you for contribution!