Add CAPTCHA

[samuelbjo]

Please att support for Captcha.

[BlackDex]

See https://github.com/dani-garcia/vaultwarden/wiki/FAQs#i-have-a-feature-request-for-the-web-vault-or-any-other-client

Also, Bitwarden did support something like this in the past, but everything regarding captcha has been removed since somewhere 2025.5 version if I'm correct.