ARQ-934: Reuse manager during whole test

Manager is created at Filter's initialization.

Additionally:
1. `CommandEventBus` now supports two-way communication. `GET` operation mode is for container-to-client commands and `PUT` operation mode for client-to-container. For client-to-container communication, client fires a `RemoteEvent` which gets propagated to the container through the `CommandEventBus`.
2. `BeforeSuite` and `AfterSuite` container events now get fired through the `CommandEventBus` on `Before` and `After` client Events.

This way the following scenario is now supported:
Fire a `RemoteEvent` on client-side which gets transfered to the Container. An Observer on the container catches this `RemoteEvent` and executes a `Command` back to the client. `TestCommandEventBus#testRemoteCommand()` ftest illustrates this functionality. 

This could be really helpful:
eg. `Proxy` could fire a `GetResponsePayload` RemoteEvent and observe for `ResponsePayloadCommand` Command from the container.