PLT-4783 Fix autofocus for "Add/Manage Members" and "More public channels" modals (#4610)

* test fix

* additional test fix

* removed commented line

* test fix

additional test fix

removed commented line

fixed sidebar, rolled back web_client fix

* fix for more_channels input focus bug

webapp/components/sidebar_header_dropdown.jsx

@@ -121,7 +121,6 @@ export default class SidebarHeaderDropdown extends React.Component {
         e.preventDefault();
 
         this.setState({
-            showDropdown: false,
             showTeamMembersModal: true
         });
     }
@@ -448,6 +447,7 @@ export default class SidebarHeaderDropdown extends React.Component {
         if (this.state.showTeamMembersModal) {
             teamMembersModal = (
                 <TeamMembersModal
+                    onLoad={this.toggleDropdown}
                     onHide={this.hideTeamMembersModal}
                     isAdmin={isAdmin}
                 />