Create persistent notification for timer function

[kevinde91]

First of all: thank you for investing your time into this app, it's improvements are very good in the last months, I think!

The timer-function works good when the app is opened, but if it's running in background the timer won't show up when the time is up.

A persistent notification which shows the name of the timer and it's remaining time would help the user to keep focused on it and perhaps bypass the battery optimization, which prevents the app to show up again when the time is up.

Thank you!

Kind regards
Kevin