Socket connect no longer synchronous and blocking

Summary:
Never really liked this code. Before this change, calls to connect were blocking.

Because of this, we had to make use of promises and a bit of really not that good-looking code.

So, this change makes connect non-blocking meaning that we make full use of our event handler.

These changes contain:
- CSR is not getting generated after each failed attempt.
- Connect is no longer blocking.
- Do not report events via the handler when explicitly disconnecting.

Reviewed By: jknoxville

Differential Revision: D46853228

fbshipit-source-id: 00e6a9c7c039a756175fe14982959e078d92bacb

xplat/Flipper/FlipperSocket.h

@@ -37,7 +37,7 @@ class FlipperSocket {
     used or error.
     @param manager An instance of FlipperConnectionManager.
   */
-  virtual bool connect(FlipperConnectionManager* manager) = 0;
+  virtual void connect(FlipperConnectionManager* manager) = 0;
   /**
     Disconnect from the endpoint.
   */