feat: avoid nesting in Behavior Factories

[Roiocam]

similar like #1444, but apply to timer and stash:

those nestings are pretty annoying, especially when i using AOSP format.

-          Behaviors.withTimers(t-> 
-              Behaviors.setup(ctx-> {
-                   // preStart something on here
-                  return new BehaviorXX();
-           }));
+          Behaviors.withTimersSetup((t, ctx) -> {
+             // preStart something on here
+              return new BehaviorXX();
+          });

[He-Pin]

@Roiocam Thanks, Tests is required too.

[pjfanning]

@Roiocam @He-Pin is this something that could be finished and added to main branch?

[He-Pin]

@Roiocam Would you like to polish this?

[He-Pin]

btw, I think we can polish more around:
refs: https://smallrye.io/smallrye-mutiny/latest/

request.ifNoItem().after(ofMillis(100))
    .failWith(() -> new TooSlowException("💥"))
    .onFailure(IOException.class).recoverWithItem(fail -> "📦")
    .subscribe().with(
        item -> log("👍 " + item),
         err -> log(err.getMessage())
    );