Add referenced users and commands warning

What does this MR do and why?

Add referenced users and commands warning

Add support for warning for referenced users and commands to both editors, and also visible when in preview mode.

Changelog: added

Screenshots or screen recordings

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 #407499