Remove visual review app token step

What does this MR do?

Because we are removing the need for the personal access token in the visual review tools, we are removing that step in the documentation.

Also adds tracking for clicking on the review app link. Related to #11944 (closed)

Closes #29067 (closed)
Closes #30132 (closed)

Screenshots

Before	After

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• [-] 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