Refactor move classes to implement respective interfaces for better structure

Plugins/PkmnLib.Plugin.Gen7/Scripts/Abilities/SlushRush.cs

@@ -6,10 +6,10 @@ namespace PkmnLib.Plugin.Gen7.Scripts.Abilities;
 /// <see href="https://bulbapedia.bulbagarden.net/wiki/Slush_Rush_(Ability)">Bulbapedia - Slush Rush</see>
 /// </summary>
 [Script(ScriptCategory.Ability, "slush_rush")]
-public class SlushRush : Script
+public class SlushRush : Script, IScriptChangeSpeed
 {
     /// <inheritdoc />
-    public override void ChangeSpeed(ITurnChoice choice, ref uint speed)
+    public void ChangeSpeed(ITurnChoice choice, ref uint speed)
     {
         if (choice.User.BattleData?.Battle.WeatherName == ScriptUtils.ResolveName<Weather.Hail>())
         {