Added support to choose between Google Recaptcha V2 and V3

[ch-rigu]

Hello,

I've added support to choose between Google reCAPTCHA V2 and V3. To make a selection, you need to specify the correct keys and set the version (v2 or v3).

I made a small modification in auth.py because it was not stopping user login if the CAPTCHA was or incorrect. The now first checks for errors, including the reCAPTCHA challenge. If there is an error, it stops; if there are no errors, it will attempt to log in.

In recaptcha.py, I've added logic to automatically select either reCAPTCHA V2 or V3.

example:

common.py

from py4web.utils.recaptcha import ReCaptcha
#for recaptcha v3
recaptcha = ReCaptcha(settings.RECAPTCHA_API_KEY_V3, settings.RECAPTCHA_API_SECRET_V3, "v3")
or 
#for recaptcha v2
recaptcha = ReCaptcha(settings.RECAPTCHA_API_KEY_V2, settings.RECAPTCHA_API_SECRET_V2, "v2")

# in the section that auth is defined
auth.extra_form_fields = {"login": [recaptcha.field], "register": [recaptcha.field], "request_reset_password": [recaptcha.field], }



auth.enable(uses=(session, T, db, recaptcha.fixture), env=dict(T=T))

auth.html

  [[try:]]
  [[=form]]
  [[except:]]
  [[pass]]
  [[=recaptcha]]

A try/except block must be implemented when the captcha is enabled (at least for now) because, when the login is successful, it throws the error: NameError: name 'form' is not defined. Using a try/except works as a patch, and the login functions normally.

Greetings.
Chris.