More abilities, refactor stealing held items

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

@@ -0,0 +1,21 @@
+using PkmnLib.Plugin.Gen7.Scripts.Pokemon;
+
+namespace PkmnLib.Plugin.Gen7.Scripts.Abilities;
+
+/// <summary>
+/// Stench is an ability that may cause the target to flinch when hit by a damaging move.
+///
+/// <see href="https://bulbapedia.bulbagarden.net/wiki/Stench_(Ability)">Bulbapedia - Stench</see>
+/// </summary>
+[Script(ScriptCategory.Ability, "stench")]
+public class Stench : Script
+{
+    /// <inheritdoc />
+    public override void OnSecondaryEffect(IExecutingMove move, IPokemon target, byte hit)
+    {
+        if (move.Battle.Random.GetInt(100) >= 10)
+            return;
+        move.Battle.EventHook.Invoke(new AbilityTriggerEvent(move.User));
+        target.Volatile.Add(new FlinchEffect());
+    }
+}