.NET 5 support

[sonnemaf]

Hi Steve,

Are you planning to create a .NET 5 version for this library? I would love to use it already in RC1.

Thanks,

Fons

[melihercan]

I have created a NuGet package and also added .NET5 support.

[conficient]

@sonnemaf if you're interested in unit testing Blazor you're much better off using the bUnit library from Egil Hansen.