Play notification sound regardless of "do not disturb"

[marbetschar]

We should play the notification sound even though the "do not disturb" mode is on. Otherwise a user does not get informed if the countdown reached 0.

Use Case

I often turn on "do not disturb" to fully focus on the task at hand, but I do have limited time to complete this task. That said, I don't want to get interrupted by any app - but I do want to be notified once the time limit is over.

[marbetschar]

The suggested approach for this is to set the notification's priority to NotificationPriority.URGENT which essentially bypasses do-not-disturb.

However, this does not work as for the currently used gala notification server in elementary Hera 5.1. We need to test, if this works as intended on the new Gtk notification server for Pantheon by building it from master and then set /org/pantheon/desktop/gala/behavior/use-new-notifications to true.

To do so we use gsettings in Terminal or dconf. For terminal:

gsettings set org.pantheon.desktop.gala.behavior use-new-notifications true

PLEASE NOTE:* At the time of this writing you need to compile and install gala as well as the new notification server from master branch. Both are not officially released yet.

[marbetschar]

Blocked by: elementary/settings-notifications#29

[marbetschar]

Added "Bypass Do Not Disturb" PR: elementary/settings-notifications#84