camel bean method references - look up bean type if possible

when there's a camel bean method reference, like the "myMethod" string here:
```
@BeanInject("myBean")
private MyBean myBean;

public void configure() {
from("direct:start")
.bean(myBean, "myMethod")
...
}
```
We can click through the reference, and it points to the `myMethod` of the `MyBean` class. But this can be an interface, or a superclass, of the actual bean class used. We can determine the real bean type if used via @BeanInject (especially if the bean name is given), and make a more specific reference.