Add e2e test and confirm support for language widget

Blocked on 📌 Get Options as buttons in Page Data form working Active - current MR includes that (squashed) as the first commit.
Will need rebase once that is in.

https://git.drupalcode.org/project/experience_builder/-/merge_requests/8... is the work for review here.

📌 Get Options as buttons in Page Data form working Active is in!

Needs rebase as described in #4.

This one seems simple enough for me to approve/review, especially because 📌 Add e2e test and confirm support for date range date list widget Active does improve upon the server-side bits that this is adding, so by landing this we gain some momentum :)

Hope @bnjmnm agrees/forgives me 😇