Fixed crash that would occur when checking for updates

[gave92]

Resolved / Related Issues
Items resolved / related issues by this PR.

• Fix crash when checking for updates. IUpdateService methods are supposed to be called from the UI thread.
• Wait for file transfers to complete before terminating process
• Restored call to UpdateTagsDb()

Validation
How did you test these changes?

• Built and ran the app

[hez2010]

I don't think all code in InitializeAppComponentsAsync should run on the UI thread. This will make the window slower to show.
How about calling IUpdateService only on the UI thread? i.e. DispatcherQueue.TryEnqueue(check for updates)

[yaira2]

The check for update code could also be deferred until everything else is loaded.

[gave92]

The code in InitializeAppComponentsAsync() is not called all on ui thread. There's a Task.Run in there. Update check is deferred untill everything else is loaded.

[hez2010]

LGTM