Feat-330/allow anonymous

[calebbourg]

Adds allow_anonymous concept to existing auth layers. Issue: #330

[calebbourg]

@GlenDC I provided the logic in ProxyAuthService's Service implementation to acknowledge allow_anonymous but did not for AsyncRequireAuthorization. It seemed it may be better handled in a given AsyncAuthorizeRequest implementation as that is where operations on header values and things like that were happening in the examples. Wasn't 100% on that choice but curious what your vision was.

Also would it make sense for me to add an example showing how this might be used?

[GlenDC]

Well done, it is exactly in the right direction and partly spot on.
Added a couple of remarks and one guide post/comment to help you reach the finish line. Thanks for your contribution and do let me know if there's any questions, remarks, feedback or anything else I can be of help with.

[GlenDC]

You are getting close.

Things to do, next to my remarks is:

• The new impl block you added for ValidateRequest needs to be removed.
• update the existing impl blocks for that trait:
  • impl<S, B, ResBody> ValidateRequest<S, B> for Bearer<ResBody> <- this replaced with the wrapper AuthorizeContext<Bearer<ResBody>>
  • impl<S, B, ResBody> ValidateRequest<S, B> for Basic<ResBody> <- this replaced with the wrapper AuthorizeContext<Basic<ResBody>>
• You also need to provide setter methods for setting that allow_anonymous on the layer + service by adding these to:
  • impl blocks for things like `impl<S, C> ValidateRequestHeaderLayer<S, AuthorizeContext>
  • impl<S, C> ValidateRequestHeader<S, AuthorizeContext<C>>
  • no need to differentiate C between Basic and Bearer here, given the constructors that we provide already limit what C can be, and C's value is not used here. So this keeps it easy and minimal

[GlenDC]

Thank you @calebbourg for your contribution, effort and patience on this one. I hope the feedback does not discourage you. As always I'm here for you if there are remarks, feedback, questions or anything else of such nature. Take care.

[calebbourg]

Thank you very much. Not discouraged at all. I welcome and appreciate the feedback. It's very helpful.

[GlenDC]

Well done, and fast indeed. Don't sweat it though, unless you're having fun :)
A couple of minor remarks, other than that I think we're good to go once these are resolved I'll give it a last review and if all is well I can merge it in if you're ok with it as well.

[GlenDC]

Well done, thank you for going the extra mile.
The added unit tests and documentation is greatly appreciated!

💯🎈