Draft: Resolve "FY25 Bug Bounty, Duo Chat '/clean' Bug"

Description

Removed the '/clean' command and refactored the existing '/clean' methods to '/clear'

Related Issues

Resolves #443511

How has this been tested?

This hasn't been tested yet, will update when it is tested.

Screenshots (if appropriate)

What CHANGELOG entry will this MR create?

• fix: Bug fix fixes - a user-facing issue in production - included in changelog
• feature: New feature - a user-facing change which adds functionality - included in changelog
• BREAKING CHANGE: (fix or feature that would cause existing functionality to change) - should bump major version, mentioned in the changelog
• None - other non-user-facing changes

Closes #1434