The Client class is part of the service context/service/client/op context hierarchy of process-related concepts and they are all decorable. The Client class also owns a transport::Session object, which implemented in a separate library and that library depends on ServiceContext.

This makes the library dependency between service_context and transport_layer_common circular, which requires the introduction of unnecessary references to executables that don't even care about either of these two libraries, such as this one.

This ticket is to find a way to decouple this circular dependency. IMO it could be done in one of two ways:

1. (Most desirable) Pull the transport::Session into a decoration of Client as opposed to ownership
2. (Undesirable as it just adds more complexity to our component graph) Pull the ServiceContext into a separate library and make Client and transport::Session both depend on it (this should only be done if there is absolutely no other way)