enforce code style rules with dotnet format

[WeihanLi]

dotnet-format is an amazing tool to enhance code style defined with .editorconfig

Maybe we could introduce dotnet-format as a ci checker to enforce the code style likes #799 etc

And from .NET 6, dotnet-format is part of the .NET SDK.

https://github.com/dotnet/format

[tg123]

it was in

csharp/.github/workflows/buildtest.yaml

Line 26 in 0f09a33

# - name: Check Format

but removed due to rule conflict