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/components/team_sidebar/team_sidebar_controller.jsx

@@ -7,6 +7,7 @@ import TeamStore from 'stores/team_store.jsx';
 import UserStore from 'stores/user_store.jsx';
 
 import * as AsyncClient from 'utils/async_client.jsx';
+import {sortTeamsByDisplayName} from 'utils/team_utils.jsx';
 import * as Utils from 'utils/utils.jsx';
 
 import $ from 'jquery';
@@ -118,7 +119,7 @@ export default class TeamSidebar extends React.Component {
         }
 
         const teams = myTeams.
-            sort(Utils.sortTeamsByDisplayName).
+            sort(sortTeamsByDisplayName).
             map((team) => {
                 return (
                     <TeamButton