Protect StripePaymentintent.process API call with ReCAPTCHA if available (requires formprotection extension and force recaptcha on contribution pages to be enabled).

Use calculated amount for multiple event participant registration. This allows use to use paymentIntent instead of setupIntent which means that cards requiring 3DSs will not fail for multiple event participant registration

If CRM.api3 fails to execute StripePaymentintent.Process display a more helpful error message instead of 'parsererror'