[Feature] WindowsProvider should display message if app is not Store associated

## Describe the problem this feature would solve

In order for the [WindowsProvider](https://docs.microsoft.com/en-us/windows/communitytoolkit/graph/authentication/windows) to work, the app must be associated with the Microsoft Store. This is done through Visual Studio as described [here](https://docs.microsoft.com/en-us/windows/mixed-reality/distribute/submitting-an-app-to-the-microsoft-store#associate-app-with-the-store) (Ignore the fact that these are the MR docs. It works the same and I couldn't find any generic guidance for UWP.)

It's not always immediately obvious to a developer that they need to do this, which can lead to folks getting stuck, "Hey, why doesn't my app work?"

It's in the docs, but is easy to miss.

## Describe the solution

See if we can throw an exception with a descriptive message telling the developer to go do the Store association.,

## Describe alternatives you've considered

None

## Additional context & Screenshots

We currently don't do anything special if the Store association is missing. Auth will just fail without obvious cause.