Add support for trusted-types and require-trusted-types-for

[kingthorin]

Adds directive and policy support for trusted-types and require-trusted-types-for, along with unit tests.

Fixes #4

Full disclosure copilot was leveraged in creating this code.

[kingthorin]

According to grok Chrome (Edge based on Chromium) and Safari do support full ABNF for trusted-types policy names, I could expand test coverage if you like.

[rbri]

@kingthorin thanks for the contribution

I'm currently on the way to version 5.0, meaning JDK 17 and major HtmlUnit changes. But this might require some weeks. do you need this soon?

[kingthorin]

No rush at all, I still have more work to do on this. I'll leverage it whenever it's released.

[kingthorin]

Note to self: Need to figure out where/how to track or handle this:

require-trusted-types-for alone → enforcement only, no restriction on names
trusted-types alone → restriction on names does nothing, enforcement inactive
trusted-types is meaningful only when require-trusted-types-for is also present