Add optional configuration to use Cloudflare Turnstile for register and login forms

[Juansecu]

For avoiding automated attacks against register and login forms, it is necessary to implement a captcha solution (in this case, Cloudflare Turnstile).

Requirements:

• This configuration must be enabled by default. Instance administrators should be able to turn it off by configuring an environment variable named SHOULD_ENABLE_CAPTCHA_PROTECTION
• The token generated by Cloudflare Turnstile must be mandatory for login and register requests. It also must be retrieved from header X-Captcha-Token

Important

This feature must be worked on only after the first stable release of the Desktop application is available, so it is possible to test whether it can support Cloudflare Turnstile or not.