Moved modifiers code to resource

Scripts/Resources/TimeModifier.cs

@@ -1,4 +1,5 @@
-using Godot;
+using Cirno.Scripts.Actors;
+using Godot;
 
 namespace Cirno.Scripts.Resources;
 
@@ -24,6 +25,16 @@ public partial class TimeModifier : Resource
     {
         return this.MemberwiseClone() as TimeModifier;
     }
+
+    public virtual void Start(Bullet bullet)
+    {
+
+    }
+
+    public virtual void Update(Bullet bullet, double delta)
+    {
+        
+    }
 }
 
 public class ModifierWrapper