Add methods to register InterceptorBindings annotation for creating intercepted instance for proxies during CDI registration and discovery.

[TheEliteGentleman]

There's no way, currently, to apply Microprofile's fault tolerance interceptors to proxies.

E.g, with Microprofile RestClient, when creating a REST client Service interface (annotated with @RegisterRestClient) and add any MP Fault Tolerance interceptor annotations on a method, e.g., @Retry, the application container will never trigger it. That's because the "proxy" attached to the service is never spotted as a CDI bean, to link it to the SPI FT interceptor.

There's the same discussion I've raised with the Microprofile WG when we implemented Langchain4J-CDI (discussion here: https://groups.google.com/g/microprofile/c/lto5IHWkN1A).

I thought of introducing the following methods:

1. Add the following on BeanConfigurator interface: BeanConfigurator<T> addInterceptorBindings(Set<InterceptorBindings> interceptorBindings);.
2. Add the following on Bean interface: public Set<Annotation> getInterceptorBindings();.

This will require that when interceptor bindings annotations exists, the bean can be added to InterceptionFactory and return an intercepted instance of the proxy, else return the proxy.

This way, any SPI can register their custom InterceptorBindings annotations by adding their InterceptorBindings annotation and it'll guarantee to be intercepted.

For context, some SPI implementations are package-private so hacking a solution isn't possible (e.g., Helidon FT).

[Ladicek]

I promised to try looking into this on SmallRye Fault Tolerance side, but didn't have the time yet. Sorry about that.

My personal take is that the problem is that the MP Fault Tolerance interceptor cannot specify all the interceptor binding annotations directly, because then users would have to also use all of them to associate the interceptor. Which is why all MP FT implementations use their own binding annotation instead. This is something we might want to change. If we did change it, MP FT implementations wouldn't have to introduce a special binding annotation and the problem would disappear.

[Ladicek]

Another option would be to add an extension point that would be notified each time InterceptionFactory.createInterceptedInstance() is called. It would be able to inspect the interceptor bindings and possibly add their own. That would then affect interceptor resolution.