TODO - Notification - Multiple balloon at once improvement

[neowutran]

See title

[neowutran]

• Keeping the priority settings
• Send notification directly when event is triggered
• Display multiple notification balloon at once since the new system allow it
• Create a queue of sound notification to avoid playing multiple sound at once
• Create a "timeout" on sound notification to avoid playing a sound too long after the actual event (due to sound queue thing) ( like, using the balloon timeout & default value if not balloon has been defined for this event)