Updates the version of XamlStyler to one with support for .NET 6.0. The version used before this depended on .NET 3.1, [which goes out of support on 2022-12-13.](https://dotnet.microsoft.com/en-us/platform/support/policy/dotnet-core)
This shouldn't be controversial as .NET 6.0 is included with VS 2022, unlike .NET 3.1.
This adds [`XamlStyler.Console`] to our solution, and calls it when we
format the code, to also format
our .xaml files.
* `XamlStyler.Console` is a dotnet tool so it needs to be restored with
`dotnet tool restore`
* I've added a set of rules to approximately follow [@cmaneu's XAML guidelines].
Those guidelines also recommend things based on the code-behind, which
this tool can't figure out, but also _don't matter that much_.
* There's an extra step to strip BOMs from the output, since Xaml Styler
adds a BOM by default. Some had them before and others didn't. BOMs
have been nothing but trouble though.
[`XamlStyler.Console`]: https://github.com/Xavalon/XamlStyler
[@cmaneu's XAML guidelines]: https://github.com/cmaneu/xaml-coding-guidelines
Jvr
Ian O'Neill
Mike Griese