Admin layout

Update AdminLayout component, but don't use PageLayout, use:

const Layout = ({route, match, t}: { route: any, match: any, t: any}) => (
  <div className="admin-layout">
    <Header menus={ <Menu t={ t } /> } />
    { renderRoutes(route.routes, match.path) }
  </div>
);

Admin header

Implement layout/admin/Header to render as displayed below:

• Use existing <UserMenuComponent and <UserLoginMenuComponent
• Use existing <LangListComponent />

To detect which menu item is active you may need to pass match to the <Header.

See details in #94 (closed)