Resolve "Use Visual Review Tools NPM package"

What does this MR do?

Currently we have duplicate code in the https://gitlab.com/gitlab-org/visual-review-tools and in CE. We want the visual-review-tools repo to be the master, and for CE to install the NPM package as a dependency and copy it over to the assets in webpack.

Related issue: visual-review-tools#9 (closed) Related issue: #66402 (closed)

What I did to test success

Before, the visual_review_toolbar.js code could be found at /assets/webpack/visual_review_toolbar.js.

After, I ran the new webpack configuration and ran the application. The asset was found at http://localhost:3000/assets/webpack/visual_review_toolbar.js. Right where it was before.

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry for user-facing changes, or community contribution. Check the link for other scenarios.
• [-] Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• [-] Style guides
• [-] Database guides
• [-] Separation of EE specific content

Performance and Testing

• [-] Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers