Remove unused chat code

What does this MR do and why?

This is a pure refactor that consolidates classes to reduce inheritance hierarchy and removes unused code.

These tools were separate at one point but they were consolidated: !143822 (merged). Asa result, the *Identifier tools are no longer needed.

Closes #457602 (closed)

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

n/a, just a refactor

How to set up and validate locally

n/a, just a refactor