* [web] Move ARS Write and Cite behind separate feature flag
* [web] Use isSplitTestEnabled function
* [web] Only load Write and Cite if project has ARS access
* [web] Enable Write and Cite ARS by default
* [web] Fix condition for loading write and cite ref sources
* [web] Remove references settings button in free projects
GitOrigin-RevId: c4f3b7c60da9864409c788dcf34bdc77347441a8