source shell improve error message when a import inside the source sc…

…ript fails

old error message would also show source not found even though the import error is caused in the source not from importing the source

custom_components/waste_collection_schedule/waste_collection_schedule/source_shell.py

@@ -217,8 +217,15 @@ def create(
             source_module: SourceModule = importlib.import_module(
                 f"waste_collection_schedule.source.{source_name}"
             )
-        except ImportError:
-            _LOGGER.error(f"source not found: {source_name}")
+        except ImportError as e:
+            if str(e).startswith(
+                f"No module named 'waste_collection_schedule.source.{source_name}'"
+            ):
+                _LOGGER.error(f"source not found: {source_name}")
+            else:
+                _LOGGER.error(
+                    f"error loading source {source_name}:\n{e} \n{traceback.format_exc()}"
+                )
             return None
 
         # create source