Retry websocket connect if error returned is 502

* Retry websocket connect if error returned is 502

* Introduce connect button on 'Disconnected' left-pane dialog

* NetworkStatus: If user clicks connect, show connecting for 5s

ts/state/ducks/user.ts

@@ -1,3 +1,6 @@
+import { trigger } from '../../shims/events';
+
+import { NoopActionType } from './noop';
 import { LocalizerType } from '../../types/Util';
 
 // State
@@ -34,6 +37,7 @@ export type UserActionType = UserChangedActionType;
 
 export const actions = {
   userChanged,
+  manualReconnect,
 };
 
 function userChanged(attributes: {
@@ -49,6 +53,15 @@ function userChanged(attributes: {
   };
 }
 
+function manualReconnect(): NoopActionType {
+  trigger('manualConnect');
+
+  return {
+    type: 'NOOP',
+    payload: null,
+  };
+}
+
 // Reducer
 
 function getEmptyState(): UserStateType {