System.UnauthorizedAccessException when trying to start a Maui WinUI app with Mobile.BuildTools.Configuration

# Description
Android + iOS Maui Mobile.BuildTools.Configuration seems to work fine! Trying to initialise the configuration manager/register the dependency causes an exception for WinUI.

Full error message:
`System.UnauthorizedAccessException: 'Access to the path 'C:\WINDOWS\system32\Configuration' is denied.'`

## Reproduction Steps

Steps to reproduce the behavior:
1. Add `Mobile.BuildTools` and `Mobile.BuildTools.Configuration` to a Maui project
2. Add your `app.config` files as raw MauiAssets
3. Register the ConfigurationManager instance with DI
4. In the platform specific Window's `App.xaml.cs`, call `ConfigurationManager.Init(true);`

## Expected Behavior

The WinUI app launches and the groundwork for using Mobile.BuildTools is setup

## Actual Behavior
The app crashes on startup with an exception:

Removing the config code and only registering the ConfigurationManager.Current dependency:

When I try debugging inside the library, it appears to be using the `CommonConfigManager` which I think is the [.NET Standard](https://github.com/dansiegel/Mobile.BuildTools/blob/master/src/Mobile.BuildTools.Configuration/Platform/NetStandard/CommonConfigManager.netstandard.cs) code path (intended for console apps/servers?).

One theory I have is that the library doesn't know about WinUI TargetFramework (https://github.com/dansiegel/Mobile.BuildTools/blob/master/src/Mobile.BuildTools.Configuration/Mobile.BuildTools.Configuration.csproj#L42) and is therefore not invoking any of the UWP code (would the UWP code work for WinUI?).

## Environment

- OS: Windows 11
- IDE: VS2022
- BuildTools Version: 2.0.245
- IDE Version: 17.4.0
- Build Target Framework: net6.0-windows10.0.19041.0

## Reproduction App
https://github.com/BurkusCat/MbtConfigurationWinUIException