[events] Support Prototype Scope

[SentryMan]

now will use a supplier using BeanScope to inject observer beans.

Given a class:

@Singleton
public class TestObserverInjection {

  void observe(@ObservesAsync String e, TestObserver observer) {}
}

This will generate

@Generated("io.avaje.inject.generator")
public final class TestObserverInjection$DI  {

  public static void build(Builder builder) {
    if (builder.isBeanAbsent(TestObserverInjection.class)) {
      var bean = new TestObserverInjection();
      builder.register(bean);
      var beanScope = builder.get(BeanScope.class);
      Supplier<TestObserver> observe$observer = () -> beanScope.get(TestObserver.class,"!observer");
      Consumer<String> observe = e -> bean.observe(e, observe$observer.get());
      builder
          .get(ObserverManager.class)
          .<String>registerObserver(
              String.class, new Observer<>(1000, true, observe, ""));
    }
  }
}