[Feature Request] Add support for netstandard2.0

[filzrev]

Currently YTest.MTP.XUnit2 supports .NET 8/.NET Framework 4.6.2 as minimum requirement.
Is it able to add netstandard2.0 as additional targets?

Background
I'm trying to test this package for BenchmarkDotNet test projects.
But BenchmarkDotNet supports old TFMs that is already out of support. (NET 5+, .NET Framework 4.6.1+, .NET Core 2.0+)

So It can't migrate test projects that using these TFM.

[Youssef1313]

Please be aware of: https://learn.microsoft.com/en-us/dotnet/standard/net-standard?tabs=net-standard-2-0

The versions listed here represent the rules that NuGet uses to determine whether a given .NET Standard library is applicable. While NuGet considers .NET Framework 4.6.1 as supporting .NET Standard 1.5 through 2.0, there are several issues with consuming .NET Standard libraries that were built for those versions from .NET Framework 4.6.1 projects. For .NET Framework projects that need to use such libraries, we recommend that you upgrade the project to target .NET Framework 4.7.2 or higher.

Aside from that, it will be problematic to add netstandard2.0 because xunit.runner.utility package uses different assembly names for different TFMs in that package. When compiling for netstandard2.0, I'm compiling against xunit.runner.utility.netstandard15 assembly. Attempting to restore that in net5.0 project for example will restore the xunit.runner.utility.netcoreapp10 assembly, and then assembly load issues will happen.

If absolutely necessary, I can try to target the specific EOL TFMs that you're looking forward to.

[Youssef1313]

I think the best course of action here is for BDN to try to reduce the range of supported TFMs. Caring about netcoreapp2.0 as of today doesn't make much sense.

[filzrev]

I think the best course of action here is for BDN to try to reduce the range of supported TFMs.

I agree too.
Supporting outdated TFMs add extra complexity and that blocking updating xUnit version to v3.

On a separate note, I would like to see support for net6.0.
It's expected to be used for testing library that support netstandard2.0 or 2.1 that targeted for Unity.