Fix list serialization for Double, Short, and Byte types

Add missing TYPE_DOUBLE, TYPE_SHORT, and TYPE_BYTE cases to readList method in UserData.java. These types were already handled in writeList but not in readList, causing deserialization to fail for lists containing these types. Also enable testLists in JmeExporterTest to verify the fix.

Co-authored-by: riccardobl <4943530+riccardobl@users.noreply.github.com>

Author: Copilot

jme3-core/src/main/java/com/jme3/scene/UserData.java

@@ -355,6 +355,15 @@ private List<?> readList(InputCapsule ic, String listName) throws IOException {
                     }
                     list.add(map);
                     break;
+                case TYPE_DOUBLE:
+                    list.add(ic.readDouble(listName + "v" + i, 0.));
+                    break;
+                case TYPE_SHORT:
+                    list.add(ic.readShort(listName + "v" + i, (short)0));
+                    break;
+                case TYPE_BYTE:
+                    list.add(ic.readByte(listName + "v" + i, (byte)0));
+                    break;
                 default:
                     throw new UnsupportedOperationException("Unknown type of stored data in a list: " + type);
             }

jme3-plugins/src/test/java/com/jme3/export/JmeExporterTest.java

@@ -139,7 +139,7 @@ public void testSaveWithNullParent() throws IOException {
     public void testExporterConsistency() {
         //
         final boolean testXML = true;
-        final boolean testLists = false;
+        final boolean testLists = true;
         final boolean testMaps = true;
         final boolean printXML = false;