Add support for .globalconfig

[ChristopherHaws]

Hey there! I have a .globalconfig file in the root of my projects repo but changes to it don't seem to get picked up by the LSP. In order for the changes to take effect, I have to restart VS Code.

I have tried adding the config file to Directory.Build.props, but the LSP still doesn't detect the changes and MSBuild complains about there being duplicate files added.

<ItemGroup Label="GlobalAnalyzers">
    <GlobalAnalyzerConfigFiles Include="$([System.IO.Path]::Combine($(MSBuildThisFileDirectory), '.globalconfig'))" />
</ItemGroup>