SIENTIAPDE-1241: refactor train_model workflow due to I/O errors.

model_manager/utils/exceptions.py

@@ -0,0 +1,12 @@
+class ModelTrainingError(Exception):
+    def __init__(self, model_trained: bool, model_saved: bool, message: str | None = None):
+        self.model_trained = model_trained
+        self.model_saved = model_saved
+
+        if message is None:
+            message = (
+                'Model training workflow failed '
+                f'(model_trained={model_trained}, model_saved={model_saved})'
+            )
+
+        super().__init__(message)