Add additional environment variables (#197)

* Added FDP_SCRIPT environment variable

* Added FDP_DATA_STORE

* Script is optional, handle as such

fair/user_config/__init__.py

@@ -627,6 +627,9 @@ def _create_environment(self) -> None:
             _new_py_path = self.local_repository
         _environment["PYTHONPATH"] = _new_py_path
         _environment["FDP_CONFIG_DIR"] = self._job_dir
+        _environment["FDP_CONFIG_NAME"] = fdp_com.USER_CONFIG_FILE
+        _environment["FDP_DATA_STORE"] = self.default_data_store
+        _environment["FDP_SCRIPT"] = self.script
         _environment["FDP_LOCAL_TOKEN"] = fdp_req.local_token()
         return _environment
 
@@ -1162,7 +1165,7 @@ def _remove_status_tags(self) -> bool:
     @property
     def script(self) -> str:
         """Retrieve path of session executable script"""
-        return self["run_metadata.script_path"]
+        return self.get("run_metadata.script_path", None)
 
     @property
     def content(self) -> typing.Dict: