Enable turn on/off Favorites/Loved feature. (#917)

* Added option to enable/disable favorites in Song

* Added option to enable/disable favorites in Artist

* Added option to enable/disable favorites in Albums and Favorites tab in sidebar

* Added option to enable/disable favorites in Player

* Set default value of enableFavourites as true

* Improved the functionality to enable/disable Favorites

* Add `EnableFavourites` config option

Co-authored-by: Deluan <deluan@navidrome.org>

ui/src/hotkeys.js

@@ -1,3 +1,4 @@
+import config from './config'
 const keyMap = {
   SHOW_HELP: { name: 'show_help', sequence: 'shift+?', group: 'Global' },
   TOGGLE_MENU: { name: 'toggle_menu', sequence: 'm', group: 'Global' },
@@ -6,7 +7,9 @@ const keyMap = {
   NEXT_SONG: { name: 'next_song', sequence: 'right', group: 'Player' },
   VOL_UP: { name: 'vol_up', sequence: '=', group: 'Player' },
   VOL_DOWN: { name: 'vol_down', sequence: '-', group: 'Player' },
-  TOGGLE_LOVE: { name: 'toggle_love', sequence: 'l', group: 'Player' },
+  ...(config.enableFavourites && {
+    TOGGLE_LOVE: { name: 'toggle_love', sequence: 'l', group: 'Player' },
+  }),
 }
 
 export { keyMap }