More abilities, refactor stealing held items

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

@@ -0,0 +1,16 @@
+namespace PkmnLib.Plugin.Gen7.Scripts.Abilities;
+
+/// <summary>
+/// Sticky Hold is an ability that prevents the Pokémon's held item from being taken.
+///
+/// <see href="https://bulbapedia.bulbagarden.net/wiki/Sticky_Hold_(Ability)">Bulbapedia - Sticky Hold</see>
+/// </summary>
+[Script(ScriptCategory.Ability, "sticky_hold")]
+public class StickyHold : Script
+{
+    /// <inheritdoc />
+    public override void PreventHeldItemSteal(IPokemon pokemon, IItem heldItem, ref bool prevent)
+    {
+        prevent = true;
+    }
+}