Resolve sidebar state issue

What does this MR do?

Correct the sidebar fixed state toggle

Are there points in the code the reviewer needs to double check?

Are there any tests we could add?

Why was this MR needed?

Because the sidebar remained in pinned stated when it was closed and was closed when unpinned

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #23988 (closed)