Add .NET 10 support

[yaqian256]

.NET 10 is released, add support for it.

• Add .net10.0 to the TargetFrameworks list for the main project
• field is now a keyword in .NET 10, update the code to fix compile errors
• Update the example and test projects to build for .NET 10 (update TargetFramework to .net10.0)
• Update the workflow to install .NET 10

[yaqian256]

Hi Chris (@chmorgan), @PhyxionNL, would you mind taking a look at this PR when you get a chance?

[PhyxionNL]

Build fails.

[yaqian256]

Build fails.

It's due to the build agent not having the .NET 10 SDK installed. I included the workflow change in my PR, but GitHub Actions appears to run workflows from the base branch (master) rather than from my PR branch. I will try splitting the workflow change into a separate PR.