Always dynamically allocate PropertyTable

- `Texture::~Texture` expects `props` to be dynamically allocated.

- `GetPropertyTable` returned a pointer to an existing `PropertyTable`
  but is expected to return a newly, dynamically allocated one.

- `PropertyTable::PropertyTable()` suggests that an empty `element`
  property is valid.

fix #46876
fix #45573

(cherry picked from commit 09bda3f140)

modules/fbx/fbx_parser/FBXProperties.h

@@ -137,6 +137,7 @@ class PropertyTable {
 public:
 	// in-memory property table with no source element
 	PropertyTable();
+	PropertyTable(const PropertyTable *templateProps);
 	PropertyTable(const ElementPtr element, const PropertyTable *templateProps);
 	~PropertyTable();