Parent task: T436085: [SPIKE] hCaptcha: investigate what is necessary to implement on wikidata.org

When the CREATE captcha trigger is active and the user lacks skipcaptcha, creating an item or property via Special:NewItem / Special:NewProperty must present a solvable hCaptcha challenge instead of failing outright. 1289917 is a reference implementation, not the definition of done validate against the AC below before closing.

Using the Extension\ConfirmEdit to handle the captcha triggering.

Acceptance criteria:

• A non-skipcaptcha user (logged-out, temp account, unconfirmed) sees the hCaptcha widget on the form when the CREATE trigger is active.
• Submitting without solving the captcha does not save, and re-shows the widget without losing the entered label/description/aliases
• Submitting with a valid captcha response saves successfully
• A skipcaptcha user sees no widget and saves exactly as today
• No regression to NewItem/NewProperty when the CREATE trigger is disabled entirely
• A proper test coverage should be implemented.
• A translatable privacy policy text with a link should be visible in the form to let users about the hCaptcha privacy policy as below.

Privacy policy text from Wikipedia:
"This site is protected by hCaptcha and its Privacy Policy and Terms of Service apply."

hCaptcha docs could be found here https://wikitech.wikimedia.org/wiki/HCaptcha