Make sure RestService Mutiny WebClient created for HTTP protocol is closing WebClient and underlying Vert.X instance

[michalvavrik]

Here you can see that client is not closed OOTB and neither is Vert.X: https://github.com/quarkus-qe/quarkus-test-framework/blob/main/quarkus-test-core/src/main/java/io/quarkus/test/bootstrap/RestService.java#L86

We already close it when we create Mutiny WebClient for HTTPS protocol: https://github.com/quarkus-qe/quarkus-test-framework/blob/main/quarkus-test-core/src/main/java/io/quarkus/test/bootstrap/RestService.java#L174

I suggest to do the same. Maybe give users to select scope (after each method, after all tests), but that is not necessary for us.