Vertx Client Engine does not handle the query params propertly.

Vertx Client Engine is not handling the Query Parameters properly. Sometimes it ignores any query paramters. 

VertX Client Engine implementation is really important for users of Quarkus that still wants to use the well-kown Resteasy but at the same time share the underlying infrastructure and threads.

Resteasy Reactive is not fully production quality and does not follow 100% the JAX-RS spec. Specially for error handling.

Created Pull Request: https://github.com/resteasy/resteasy/pull/2890

• Adds a fix to add query params on request.
• Check if user agent exists to avoid duplicate agent.
• Force add vertx handler to use in case that there is no executor service to deserialize request.