Support new Navigation side toolbar

[andybroomfield]

Couple of issues noticed when trying the new experimental Navigation toolbar

• Menu link group raises an error, see Compatability with Navigation localgov_menu_link_group#35
• After applying a hotfix to Menu link group there are several empty menu groups in the menu becuase the add content menu is missing in navigation (replaced with the create menu)
• User roles dont have the permission 'Access navigation bar'

Suggest we also add Location and Alert banner to the create menu.
Theres also no direct access to things like alert banners anymore, since that has to go through content (no content menu).