Refactor rules acknowledgment logic and update role assignment behavior

- Removed the `on_presentation_message` function to streamline role assignment processes.
- Updated the `assign_rules_arrival_on_join` function to clarify its purpose, focusing solely on assigning the arrival role upon member join.
- Adjusted success message generation for role validation to enhance clarity and user experience.
- Modified configuration settings and web templates to reflect the updated role assignment behavior, ensuring accurate user guidance.

webapp/configurations.py

@@ -50,7 +50,6 @@ def updateConfiguration():
 		'auto_rooms_enable': 'auto_rooms_channel_id',
 		'twitch_commands_enable': 'twitch_channel',
 		'rules_ack_enable': 'rules_channel_id',
-		'rules_arrival_on_join_enable': 'rules_ack_section_in_form',
 	}
 	
 	# Ne mettre à jour les rôles staff que si la liste a été rendue dans le formulaire.