Add keys to Toolbar renderers

[colin-grant-work]

What it does

Since #10731, there has been an error logged about missing key properties in a React-rendered div:

This PR adds key properties to several divs rendered by the Toolbar, and removes the error log.

How to test

1. Start the application.
2. Assert that there are no React errors about missing keys.
3. Show and hide the Toolbar.
4. Assert that there are still no React errors about missing keys.

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[msujew]

LGTM 👍