[MM-58693] Fix some issues with Windows notifications

[devinbinnie]

Summary

Found a few issues with reporting notifications on Windows and a small bug that I wanted to fix:

• Sometimes Windows will fire both the show and failed events when a notification fails to show due to permissions not being enabled for Mattermost in Windows. This was then always being reported as a success when it should be not_sent, so I had to add a timeout to have the show callback wait for the failed one to potentially run (not an elegant solution)
• Windows would return failed when the notification fails the permission check. This should now be reported as not_sent as it is a user choice not to send the notification
• Our DND check for priority was returning the opposite of what it should, so I've swapped the flag.

Ticket Link

https://mattermost.atlassian.net/browse/MM-58693

Fixed an issue with DND mode on Windows

[devinbinnie]

Is this a recent regression or something that we tracked down with recent metrics and added logging? Can we create a ticket for tracking purposes on notification fixes?

I just found this while testing the notifications manually, but I can add a ticket for it.

[devinbinnie]

Do we want to include this in the dot release as well?

cc @amyblais

[amyblais]

Sounds good.

[mattermost-build]

Cherry pick is scheduled.