connectToServer is not thread safe due to thread-safety issues with TyrusClientEngineState

Workflow:
1. Create 2 threads, each having its own instance of ClientManager, AuthConfig and Authenticator
2. When calling connectToServer on both threads simultaneously, its possible the AuthConfig Authenticator instance from Thread A is used when trying to connect on Thread B

The issue is with the TyrusClientEngineState enum and the fact the code is storing the authenticator and wwwAuth header and passing it around on the static enums.