Please provide core libraries for .NET Framework 4.8.1

[dallmair]

We'd like to use NQuery in a Microsoft Office add-in. The Microsoft Office extensibility story is complex, but there is VSTO and VSTO builds on .NET Framework. At the same time, coexistence of the .NET and .NET Framework runtimes in the same process is not supported:

• Add support for .NET Core and .NET Framework side-by-side in same process dotnet/runtime#53729
• COM hosting breaks with multiple versions of .NET being loaded dotnet/runtime#49686
• .Net 5 and further VSTO dotnet/core#5156

Therefore we target .NET Framework 4.8.1.

At the moment, NQuery is only available on .NET 8+. Please consider making it available on .NET 4.8.1 as well. Core libraries for evaluation are enough (NQuery, NQuery.Data, NQuery.Dynamic); The test/authoring/UI libraries and viewer are not necessary on that platform.

Thanks!