feat: only handlers with same named or unqualified

[sdelamo]

see: #236

Given an application with two skills configured.

alexa:
  skills:
    helloworld: 
      skill-id: 'xxx'   
    hellomoon: 
      skill-id: 'xxx'   

We may have a LaunchRequest handler for helloworld:

@Named("helloworld")
@Singleton
public class LaunchRequestHandler implements RequestHandler {

    @Override
    public boolean canHandle(HandlerInput input) {
        return input.matches(Predicates.requestType(LaunchRequest.class));
    }

    @Override
    public Optional<Response> handle(HandlerInput input) {
        String speechText = "Welcome to Hello World";
        return input.getResponseBuilder()
                .withSpeech(speechText)
                .build();
    }
}

And a different LaunchRequest handler for hellomoon:

@Named("hellomoon")
@Singleton
public class LaunchRequestHandler implements RequestHandler {

    @Override
    public boolean canHandle(HandlerInput input) {
        return input.matches(Predicates.requestType(LaunchRequest.class));
    }

    @Override
    public Optional<Response> handle(HandlerInput input) {
        String speechText = "Welcome to Hello Moon";
        return input.getResponseBuilder()
                .withSpeech(speechText)
                .build();
    }
}

However, we may want to share the same session handler to end the session:

@Singleton
public class SessionEndedRequestHandler implements RequestHandler {

    @Override
    public boolean canHandle(HandlerInput input) {
        return input.matches(requestType(SessionEndedRequest.class));
    }

    @Override
    public Optional<Response> handle(HandlerInput input) {
        // any cleanup logic goes here
        return input.getResponseBuilder().build();
    }
}

if a RequestHandler bean is not qualified with name, I consider it applies to every Alexa Skill.
If a RequestHandler is qualfied with a name, it applies only to the Alexa Skill matching that name.

We don't have a method in ApplicationContext such as applicationContext.getBeansOfTypeNotQualifiedBy(RequestHandler.class, Qualifiers.byName(name))); so this code is a bit more hairy.