reCAPTCHA validation refactoring

[naydav]

Adapt code to new interface

/**
 * Validate reCAPTCHA response
 *
 * @api
 */
interface ValidatorInterface
{
    /**
     * Return true if reCAPTCHA validation has passed
     *
     * @param string $reCaptchaResponse
     * @param ValidationConfigInterface $validationConfig
     * @return ValidationResult
     */
    public function isValid(
        string $reCaptchaResponse,
        ValidationConfigInterface $validationConfig
    ): ValidationResult;
}