[VOL-1588] Improve Flow Add performance

This update consists of the following:
1) Update the performance when adding a flow to a logical device,
decomposing the flow into parent and child device and sending the
flow to the adapters.
2) Format a number of files as per GO fmt.
3) Ensure the device graph cache gets updated when a new port is
added to the graph that belongs to an existing device in cache.

The flow update/deletion performance will be addressed in a separate
commit.

Change-Id: I2eb663cc73eef9fc6172203ed88a35726f5fe008
diff --git a/adapters/simulated_onu/adaptercore/device_handler.go b/adapters/simulated_onu/adaptercore/device_handler.go
index 217614c..ec00426 100644
--- a/adapters/simulated_onu/adaptercore/device_handler.go
+++ b/adapters/simulated_onu/adaptercore/device_handler.go
@@ -139,7 +139,7 @@
 		AdminState: voltha.AdminState_ENABLED,
 		OperStatus: voltha.OperStatus_ACTIVE,
 		Peers: []*voltha.Port_PeerPort{{DeviceId: cloned.ParentId, // Peer device  is OLT
-			PortNo: uni_port}},            // Peer port is UNI port
+			PortNo: uni_port}}, // Peer port is UNI port
 	}
 
 	// Synchronous call to update device - this method is run in its own go routine