Added Admin settings opening in new tab

app/soapbox/components/sidebar_menu.js

@@ -172,7 +172,7 @@ class SidebarMenu extends ImmutablePureComponent {
                 <Icon id='filter' />
                 <span className='sidebar-menu-item__title'>{intl.formatMessage(messages.filters)}</span>
               </NavLink> */}
-              { isStaff && <a className='sidebar-menu-item' href={'/pleroma/admin/'} onClick={onClose}>
+              { isStaff && <a className='sidebar-menu-item' href={'/pleroma/admin/'} target='_blank' onClick={onClose}>
                 <Icon id='shield' />
                 <span className='sidebar-menu-item__title'>{intl.formatMessage(messages.admin_settings)}</span>
               </a> }

app/soapbox/features/account/components/header.js

@@ -166,7 +166,7 @@ class Header extends ImmutablePureComponent {
 
     if (account.get('id') !== me && isStaff) {
       menu.push(null);
-      menu.push({ text: intl.formatMessage(messages.admin_account, { name: account.get('username') }), href: `/pleroma/admin/#/users/${account.get('id')}/` });
+      menu.push({ text: intl.formatMessage(messages.admin_account, { name: account.get('username') }), href: `/pleroma/admin/#/users/${account.get('id')}/`, newTab: true });
     }
 
     return menu;

app/soapbox/features/compose/components/action_bar.js

@@ -80,7 +80,7 @@ class ActionBar extends React.PureComponent {
     menu.push(null);
     menu.push({ text: intl.formatMessage(messages.keyboard_shortcuts), action: this.handleHotkeyClick });
     if (isStaff) {
-      menu.push({ text: intl.formatMessage(messages.admin_settings), href: '/pleroma/admin/' });
+      menu.push({ text: intl.formatMessage(messages.admin_settings), href: '/pleroma/admin/', newTab: true });
     }
     menu.push({ text: intl.formatMessage(messages.preferences), to: '/settings/preferences' });
     menu.push({ text: intl.formatMessage(messages.security), to: '/auth/edit' });