improve informer creation when same resources are watched

[viktorpergjoka]

Every @Watch annotated methods creates one informer, because every resource needs its own informer.

for example:

@Informer 
public class Test {

    @Watch(event = EventType.ADD, resource = Pod.class)
    public void added(Pod pod){ 
    }

    @Watch(event = EventType.UPDATE, resource = Pod.class)
    public void updated(Pod pod, Pod pod2){
    }

    @Watch(event = EventType.DELETE, resource = Pod.class)
    public void deleted(Pod pod){}
}

This creates 3 informer. But since all 3 Watches are watching the same resource (in this case a Pod), one informer is sufficient.

Another example:

@Informer
public class Test {

    @Watch(event = EventType.ADD, resource = Pod.class)
    public void added(Pod pod){ 
    }

    @Watch(event = EventType.UPDATE, resource = Pod.class)
    public void updated(Pod pod, Pod pod2){
    }

    @Watch(event = EventType.DELETE, resource = Secret.class)
    public void deleted(Secret secret){}
}

This creates also 3 informers. 2 are at a minimum needed because we have 2 different resources (Pod and Secret).
The 2 Watch annotated methods for the Pods could also be created in one informer.