Summary:
Introduce ServerAdapter which should be used as a base class for different server implementations e.g. RSocket, WebSocket.
The type is not used elsewhere at this point but this is a good chance to look at the API and suggest changes and/or improvements.
Reviewed By: passy
Differential Revision: D29958434
fbshipit-source-id: 50ba46332d40e836b0a87bcf354d3237bf8fe7c5
b0e47bf75e