Remove sound for new notification, add a colored dot instead

[unrevised6419]

Remove the sound that is played when a new notification is received, replace the sound with a colored dot on the icon

Treb de inlaturat sunetul cand apare o notificare noua :D Un cerculet colorat e de ajuns ca sa instiinteze utilizatorul.

Extracted from https://docs.google.com/document/d/150Jb-r3-96bOsvBPLxNrQoYb9BoPnIYLj5uzB8tMDUs