Make DataUpdateHeartbeat event names more consistent (#141)

This also allows differentiating between eglpc.DataUpdateHeartbeat and
cslpc.DataUpdateHeartbeat events.

While syncing my branch on dev, I saw
#137 and noticed that the
DataUpdateHeartbeat events for eg/lpc and cs/lpc used the same
identifier which means they can't be differentiated from another over
e.g. json-rpc. I also took the liberty of changing the "uclppserver-"
identifier to "cs-lpp-" to make it consistent with the other event
names.

usecases/cs/lpp/types.go

@@ -43,5 +43,5 @@ const (
 	// E.g. going into or out of the Failsafe state
 	//
 	// Use Case LPP, Scenario 3
-	DataUpdateHeartbeat api.EventType = "uclppserver-DataUpdateHeartbeat"
+	DataUpdateHeartbeat api.EventType = "cs-lpp-DataUpdateHeartbeat"
 )

usecases/eg/lpc/types.go

@@ -35,5 +35,5 @@ const (
 	// E.g. going into or out of the Failsafe state
 	//
 	// Use Case LPC, Scenario 3
-	DataUpdateHeartbeat api.EventType = "cs-lpc-DataUpdateHeartbeat"
+	DataUpdateHeartbeat api.EventType = "eg-lpc-DataUpdateHeartbeat"
 )

usecases/eg/lpp/types.go

@@ -35,5 +35,5 @@ const (
 	// E.g. going into or out of the Failsafe state
 	//
 	// Use Case LPP, Scenario 3
-	DataUpdateHeartbeat api.EventType = "cs-lpp-DataUpdateHeartbeat"
+	DataUpdateHeartbeat api.EventType = "eg-lpp-DataUpdateHeartbeat"
 )