Scenario: Clean DB add minimal comment.

src/Model/Scenario.py

@@ -228,6 +228,8 @@ class Scenario(SQLSubModel):
 
         for table in tables:
             if self.parent is None:
+                # This scenario is the default scenario, so we can
+                # delete all data marked as deleted
                 execute(
                     f"DELETE FROM {table} " +
                     f"WHERE scenario = {self.id} " +
@@ -235,6 +237,8 @@ class Scenario(SQLSubModel):
                 )
                 continue
 
+            # Select pamhyr_id for each deleted data in this scenario
+            # who do not exists into parents scenarios
             ids = execute(
                 f"""
                   SELECT pamhyr_id FROM {table}