New messages and notification sound selection menu.

Now, the notification sound can be selected from a menu. The configuration of whether to keep the list of sounds or to use the menu can be done from the config.yml file.

Also, a problem that I discovered during tests has been fixed, which was that when the plugin was reloaded, it did not add the notification sound to online users in the userdata.yml file. Now the code works fine.

All console messages were also removed.