Adds improved tooltip to invalid encodedPattern (#2992)

* Adds improved tooltip to invalid encodedPattern

This also fixes that encodedPattern might be shown as valid,
even though one or more input or output item is missing.

src/main/java/appeng/client/render/crafting/ItemEncodedPatternBakedModel.java

@@ -227,7 +227,7 @@ class ItemEncodedPatternBakedModel implements IBakedModel
 			{
 				ItemEncodedPattern iep = (ItemEncodedPattern) stack.getItem();
 				ItemStack output = iep.getOutput( stack );
-				if( output != null )
+				if( !output.isEmpty() )
 				{
 					IBakedModel realModel = Minecraft.getMinecraft().getRenderItem().getItemModelMesher().getItemModel( output );
 					// Give the item model a chance to handle the overrides as well