Consider adding .exe to nupkg

[jlperkins]

There has been a customer request to add sbom-tool.exe to the NuGet package we release, instead of just including the .dll. We should evaluate how much of a lift this would be and consider implementing. The other team is not blocked on this, but their workaround takes some doing, so they have requested that we add the .exe to the package.

This request comes from Shivansh Mishra of the 'Kit build infra' team. They are hoping to consume our tool in an OS repo without having to manually grab it and put it into a vpack.