#3802 if cr has requested reviewers, only they can approve

[chpy04]

Changes

If a CR has no requested reviewers, the functionality remains the same. If it has requested reviewers, only they can approve the CR

Notes

also added tool tip to the actions menu to tell users why they can't approve

Screenshots

Checklist

It can be helpful to check the Checks and Files changed tabs.
Please review the contributor guide and reach out to your Tech Lead if anything is unclear.
Please request reviewers and ping on slack only after you've gone through this whole checklist.

• All commits are tagged with the ticket number
• No linting errors / newline at end of file warnings
• All code follows repository-configured prettier formatting
• No merge conflicts
• All checks passing
• Screenshots of UI changes (see Screenshots section)
• Remove any non-applicable sections of this template
• Assign the PR to yourself
• No yarn.lock changes (unless dependencies have changed)
• Request reviewers & ping on Slack
• PR is linked to the ticket (fill in the closes line below)

Closes #3802