PLT-2713/PLT-6028 Added System Users list to System Console (#5882)

* PLT-2713 Added ability for admins to list users not in any team

* Updated style of unit test

* Split SearchableUserList to give better control over its properties

* Added users without any teams to the user store

* Added ManageUsers page

* Renamed ManageUsers to SystemUsers

* Added ability to search by user id in SystemUsers page

* Added SystemUsersDropdown

* Removed unnecessary injectIntl

* Created TeamUtils

* Reduced scope of system console heading CSS

* Added team filter to TeamAnalytics page

* Updated admin console sidebar

* Removed unnecessary TODO

* Removed unused reference to deleted modal

* Fixed system console sidebar not scrolling on first load

* Fixed TeamAnalytics page not rendering on first load

* Fixed chart.js throwing an error when switching between teams

* Changed TeamAnalytics header to show the team's display name

* Fixed appearance of TeamAnalytics and SystemUsers on small screen widths

* Fixed placement of 'No users found' message

* Fixed teams not appearing in SystemUsers on first load

* Updated user count text for SystemUsers

* Changed search by id fallback to trigger less often

* Fixed SystemUsers list items not updating when searching

* Fixed localization strings for SystemUsers page

webapp/utils/async_client.jsx

@@ -314,7 +314,7 @@ export function getChannelMember(channelId, userId) {
     });
 }
 
-export function getUser(userId) {
+export function getUser(userId, success, error) {
     const callName = `getUser${userId}`;
 
     if (isCallInProgress(callName)) {
@@ -331,10 +331,18 @@ export function getUser(userId) {
                 type: ActionTypes.RECEIVED_PROFILE,
                 profile: data
             });
+
+            if (success) {
+                success(data);
+            }
         },
         (err) => {
-            callTracker[callName] = 0;
-            dispatchError(err, 'getUser');
+            if (error) {
+                error(err);
+            } else {
+                callTracker[callName] = 0;
+                dispatchError(err, 'getUser');
+            }
         }
     );
 }