[gnome-games] game: Add is_favorite property

[Alexander Mikhaylenko <alexm src gnome org>]

commit 1ce527981712b301d97fe39e287e404123ed522a
Author: Neville <nevilleantony98 gmail com>
Date:   Thu Jun 18 21:37:09 2020 +0530

    game: Add is_favorite property
    
    This will be used in the upcoming commits to set if a game is favorite.
    This will be later bound to GameIconView's is_favorite prop to show a
    star for favorited games.

 src/core/game.vala | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/core/game.vala b/src/core/game.vala
index 0499abec..9422f258 100644
--- a/src/core/game.vala
+++ b/src/core/game.vala
@@ -27,6 +27,7 @@ public class Games.Game : Object {
        public Uri uri { get; private set; }
        public Platform platform { get; private set; }
        public MediaSet? media_set { get; set; }
+       public bool is_favorite { get; set; }
 
        private Title game_title;
        private Icon game_icon;