feat: add palettes and enums for MC 1.21.11 (protocol 774)

Add 17 new items (spears, nautilus armor, spawn eggs, netherite horse armor),
4 new entities (CamelHusk, Nautilus, Parched, ZombieNautilus), and 2 new
entity metadata serializer types (ZombieNautilusVariant, HumanoidArm).

Generated ItemPalette12111 (1505 items), EntityPalette12111 (157 entities),
and EntityMetadataPalette12111 (39 serializers) from server reports.

Made-with: Cursor

MinecraftClient/Mapping/EntityMetaDataType.cs

@@ -116,5 +116,13 @@ public enum EntityMetaDataType
     /// <summary>
     /// Either&lt;GameProfile, Partial&gt; + PlayerSkin.Patch (1.21.9+)
     /// </summary>
-    ResolvableProfile
+    ResolvableProfile,
+    /// <summary>
+    /// VarInt (1.21.11+, holder registry ID)
+    /// </summary>
+    ZombieNautilusVariant,
+    /// <summary>
+    /// VarInt (1.21.11+, 0=LEFT, 1=RIGHT)
+    /// </summary>
+    HumanoidArm
 }