QmlDesigner: Do not allow baseState as id

Using this as id will lead to bugs.

Change-Id: I76997a31e290e0cd67688fecdb1e9521c88481da
Reviewed-by: Henning Gründl <henning.gruendl@qt.io>

src/plugins/qmldesigner/designercore/model/modelnode.cpp

@@ -196,7 +196,8 @@ static bool isIdToAvoid(const QString& id)
         "texture",
         "shaderInfo",
         "sprite",
-        "spriteSequence"
+        "spriteSequence",
+        "baseState"
     };
 
     return ids.contains(id);