feat(http): add cell properties to dashboard response

[dearyhud]

Closes #16052

Describe your proposed changes here.
Adds an optional ?include=properties query string to GET /dashboards/:dashboardID that returns each cells properties

• CHANGELOG.md updated with a link to the PR (not the Issue)
• Well-formatted commit messages
• Rebased/mergeable
• Tests pass
• http/swagger.yml updated (if modified Go structs or API)
• Documentation updated or issue created (provide link to issue/pr)
• Signed CLA (if not already signed)

[imogenkinsman]

Need to add the new param to our swagger :)

[ebb-tide]

This is awesome !! Thanks for doing this!

[jsteenb2]

lets give it a try