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/common/ContextMenus.js

@@ -133,7 +133,7 @@ const ContextMenu = ({
       <LoveButton
         record={record}
         resource={resource}
-        visible={showLove}
+        visible={config.enableFavourites && showLove}
         color={color}
       />
       <IconButton

ui/src/common/SongContextMenu.js

@@ -87,7 +87,11 @@ export const SongContextMenu = ({
 
   return (
     <span className={clsx(classes.noWrap, className)}>
-      <LoveButton record={record} resource={resource} visible={showLove} />
+      <LoveButton
+        record={record}
+        resource={resource}
+        visible={config.enableFavourites && showLove}
+      />
       <IconButton onClick={handleClick} size={'small'}>
         <MoreVertIcon fontSize={'small'} />
       </IconButton>