[Feature request] disable transport and use vert.x like a `akka-actor`?

#### Describe the feature

Currently, seems like the transport is always on, and there is no way to disable the nio selector. with 40000 vertical

```java
14:19:16.255 [vert.x-eventloop-thread-8] DEBUG io.netty.channel.nio.NioEventLoop - Selector.select() returned prematurely 3 times in a row for Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@30cefacc.
14:19:16.319 [vert.x-eventloop-thread-8] DEBUG io.netty.channel.nio.NioEventLoop - Selector.select() returned prematurely 3 times in a row for Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@30cefacc.
14:19:16.319 [vert.x-eventloop-thread-9] DEBUG io.netty.channel.nio.NioEventLoop - Selector.select() returned prematurely 3 times in a row for Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@1c10d17b.
14:19:16.574 [vert.x-eventloop-thread-20] DEBUG io.netty.channel.nio.NioEventLoop - Selector.select() returned prematurely 3 times in a row for Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@59847757.
14:19:16.620 [vert.x-eventloop-thread-14] DEBUG io.netty.channel.nio.NioEventLoop - Selector.select() returned prematurely 3 times in a row for Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@5d38e5e.
ticked:34
ticked:34
ticked:34
14:19:16.899 [vert.x-eventloop-thread-9] DEBUG io.netty.channel.nio.NioEventLoop - Selector.select() returned prematurely 3 times in a row for Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@1c10d17b.
```
#### Use cases

I am writing a lock-step service with vert.x, which want to use vert.x's Vertical as an Akka's Actor and Eventbus as Akka's EventStream, And don't need to involve the networking part.

#### Contribution

Yes