Proper notification behaivor

[mablae]

Is your feature request related to a problem? Please describe.
It would be nice to not get distracted with notifications while working all the time.

Describe the solution you'd like
Save last interaction with the notification popup and only show a popup after the threshold defined in
the settings is reached. #30

Also, if no interaction has been done with an active notification popup, do not open further popups. Only allow one popup to be open at a time #59

Additional context
I am using Ubuntu 18.04

[deluxor]

And would be nice to fix the amount of notifications shown on screen!

[robinduckett]

Also new notifications for linux kernel versions that you don't have running should not be shown. If I have 4.18 and 4.19 installed, but I'm not using 4.19 because of a driver issue and I'm currently using 4.18, I'd like to see notifications for 4.18 but not 4.19