SIENTIAPDE-1251: Implement ML model training activity and repository

This commit introduces the 'Training' activity and 'TrainingRepository' for handling ML model training operations within the Model Manager system.

- Added model_manager/activities/training.py for the Training activity, which extends BaseActivity and integrates with Temporal workflows.
- Added model_manager/utils/repository/training_repository.py for the TrainingRepository, which encapsulates the core training logic.
- Updated model_manager/activities/activities.py to include the Training activity in the main activities orchestrator.
- Updated README.md to document the new 'Training' component.
- Added unit tests for the new activity and repository.

tests/activities/test_activities.py

@@ -6,14 +6,20 @@ from model_manager.activities.activities import Activities
 from model_manager.activities.experiment_tracking import ExperimentTracking
 from model_manager.activities.gates import Gates
 from model_manager.activities.mlflow import MLFlow
+from model_manager.activities.training import Training
 
 
 @patch('model_manager.activities.activities.ExperimentTracking.__init__')
 @patch('model_manager.activities.activities.MLFlow.__init__')
 @patch('model_manager.activities.activities.MinIO.__init__')
 @patch('model_manager.activities.activities.Gates.__init__')
+@patch('model_manager.activities.activities.Training.__init__')
 def test___init__(
-    mock_gates_init, mock_minio_init, mock_mlflow_init, mock_experiment_tracking_init
+    mock_training_init,
+    mock_gates_init,
+    mock_minio_init,
+    mock_mlflow_init,
+    mock_experiment_tracking_init,
 ):
     postgres_config = {
         'host': 'localhost',
@@ -54,6 +60,7 @@ def test___init__(
     assert isinstance(activities, ExperimentTracking)
     assert isinstance(activities, MLFlow)
     assert isinstance(activities, Gates)
+    assert isinstance(activities, Training)
 
     mock_experiment_tracking_init.assert_called_once_with(
         ANY,
@@ -97,6 +104,10 @@ def test___init__(
         ANY, logger=logger, notification_handler=notification_handler
     )
 
+    mock_training_init.assert_called_once_with(
+        ANY, logger=logger, notification_handler=notification_handler
+    )
+
 
 @mark.asyncio
 @patch('model_manager.activities.activities.ExperimentTracking', return_value=MagicMock())