[Feature Request] Buttons on Popup/Notifications

Hello, I'm a happy ArchLinux user of OpenSnitch under Xfce desktop, and I want to ask for a new feature.
Following issue #476, I'd like to suggest to have an option to enable notification using a notification balloon.

The notification balloon would have 3 three buttons "Deny" "Allow" "Expert"
"Expert" button (or whatever name you have in mind) will open the popup dialog which we currently have.

**Reason: Intrusiveness**
While Notification Balloon will be on the top layer of the display, just as the current popup dialog, it will not be intrusive in the sense that it will not cause a fault of a current user's action.

**Example: Intrusiveness**
User is in the middle of adding tags to a bookmark in a web browser, and the popup dialog of OpenSnitch just caused it to be closed.