Add method to get unquoted fragment

The fragment can be encoded but some users need the unquoted
form.

Author: timj

python/lsst/resources/_resourcePath.py

@@ -393,9 +393,14 @@ def is_root(self) -> bool:
 
     @property
     def fragment(self) -> str:
-        """Return the fragment component of the URI."""
+        """Return the fragment component of the URI. May be quoted."""
         return self._uri.fragment
 
+    @property
+    def unquoted_fragment(self) -> str:
+        """Return unquoted fragment."""
+        return urllib.parse.unquote(self.fragment)
+
     @property
     def params(self) -> str:
         """Return any parameters included in the URI."""