Apply suggestions from PR

- Open and save the test map so we know for certain it's in line with Tiled output
- If we can't find a property type on a class property, default to an empty string instead of "class"

assets/tiled_class_property.tmx

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<map version="1.5" tiledversion="1.7.2" orientation="orthogonal" renderorder="right-down" width="2" height="2" tilewidth="32" tileheight="32" infinite="0" nextlayerid="3" nextobjectid="4">
+<map version="1.10" tiledversion="1.10.2" orientation="orthogonal" renderorder="right-down" width="2" height="2" tilewidth="32" tileheight="32" infinite="0" nextlayerid="3" nextobjectid="4">
  <layer id="1" name="Tile Layer 1" width="2" height="2">
   <data encoding="csv">
 0,0,
@@ -11,7 +11,7 @@
    <properties>
     <property name="class property" type="class" propertytype="test_type">
      <properties>
-      <property name="test_property_1" value="3" type="int"/>
+      <property name="test_property_1" type="int" value="3"/>
      </properties>
     </property>
     <property name="empty property" type="class" propertytype="empty_type"/>

src/properties.rs

@@ -163,7 +163,7 @@ pub(crate) fn parse_properties(
                     HashMap::new()
                 };
                 p.insert(k, PropertyValue::ClassValue {
-                    property_type: p_t.unwrap_or_else(|| "class".to_owned()),
+                    property_type: p_t.unwrap_or_default(),
                     properties,
                 });
                 return Ok(());