Move Playlists to the sidebar menu (#1339)

* Show playlists in sidebar menu

* Fix menu

* Refresh playlist submenu when adding new playlist

* Group shared playlists below user's playlists

* Fix text overflow in menu options

* Add button in playlist menu to go to Playlists list

* Add config option `DevSidebarPlaylists` to enable this feature (default false)

ui/src/App.js

@@ -91,7 +91,11 @@ const Admin = (props) => {
         <Resource name="album" {...album} options={{ subMenu: 'albumList' }} />,
         <Resource name="artist" {...artist} />,
         <Resource name="song" {...song} />,
-        <Resource name="playlist" {...playlist} />,
+        <Resource
+          name="playlist"
+          {...playlist}
+          options={{ subMenu: 'playlist' }}
+        />,
         <Resource name="user" {...user} options={{ subMenu: 'settings' }} />,
         <Resource
           name="player"