Add support for Trusted Types

[bjarkler]

Summary

I'm submitting a:

• bug report
• feature request
• question / support request
• other

Description

Trusted Types is a Content Security Policy feature that allows web application owners to guard against insecure usage of dangerous DOM APIs and prevent Cross-Site Scripting vulnerabilities. The default version of the reCAPTCHA library is not compatible with Trusted Types, but can be made compatible by adding &trustedtypes=true as a query parameter when loading the library.

Currently applications using ng-recaptcha cannot adopt Trusted Types because it doesn't seem possible to add that query parameter. To fix this I propose either always setting the parameter (there shouldn't be any downsides) or making it configurable as part of the ng-recaptcha interface.

I'd be happy to send a PR implementing this.

[DethAriel]

Hello @bjarkler! Thank you for submitting this, as well as providing the relevant documentation and code references!

This does indeed sound like a worthy addition with no visible downsides, so let me make this happen.