[Bug] Alert rule groups block deletion of folders when removed at the same time

[theSuess]

Describe the bug
As folder deletion is not blocked with a finalizer it happens instantly. At this point, the finalizer is no longer able to find the folder and assumes there is nothing to clean up. This results in the folder never getting deleted from the instance

Version
master

To Reproduce
Steps to reproduce the behavior:

1. Create an alert rule group & folder
2. Delete both at the same time
3. See that the resources are removed but still exist in grafana

Expected behavior
Folder deletion should block until removed from all instances

Suspect component/Location where the bug might be occurring
It's possible to work around this issue in the finalizer of the alert rule group. This however would be very complex as we'd have to re-parse the folders from the Grafana instance

[theSuess]

This is solved through #1728