Added an easy way to add captcha to any form

[roadster31]

This PR adds a specific form validator to the module , which extends the base TheliaFormValidator: ReCaptchaFormValidator.
This form validator dispatches the CHECK_CAPTCHA_EVENT event if the g-recaptcha-response form field is defined in the request, and throw an exception if a suspicious action is detected.

Thus, adding {hook name="recaptcha.check"} to any form will add a ReCaptcha check to this form without the need to update the form validation code.

[lopes-vincent]

I think this is dangerous to do this because this will not work if another module override the thelia form validator

[roadster31]

True, but it makes the module usable almost out of the box (inserting a hook déclaration in a template is enough), instead of having to code something.
Additionally, the module could not be used easily for base Thelia forms. This change make it usable in these forms too.

[lopes-vincent]

Yes I understand your PR and this is very great but like I said it's dangerous because you can think you are protected but you are not because another module override the form validator.
Maybe we can add a warning message in this case ? (I don't know if we can check if another module override this service)

[TheCoreDev31]

Nowadays, ReCaptcha is a must-have Thelia module (it should be included directly in Thelia) so any solution for making module's integration easier would be appreciated 👍

[lopes-vincent]

Sorry we are not going to include a module who is connected to a proprietary service in Thelia.
I agreed we need a more simple way to add this module to a form but like I explain this PR is not a good solution,
the service can be override by another module, so it will be inefficient and if a bot remove the field g-recaptcha-response the module will not check the captcha and will be inefficient too.