stream: set connection monitor delay. (#1120)

* stream: set connection monitor delay.

- this fixes a bug where the connection monitor delay config value does not
get set to the websocket on intialization.

* multi: add connection monitor delay to exchange config.

- this adds the connection monitor delay config option to the exchange type.
- the validate function of the exchange type has been updated to validate the
connection monitor delay value as well.

* multi: resolve review issues.

exchanges/exchange_test.go

@@ -1198,6 +1198,7 @@ func TestSetupDefaults(t *testing.T) {
 		API: config.APIConfig{
 			AuthenticatedSupport: true,
 		},
+		ConnectionMonitorDelay: time.Second * 5,
 	}
 
 	err = b.SetupDefaults(&cfg)