CLI: replace old .NET Framework manifest-signing (ClickOnce) code with dotnet-mage

We shouldn't own copies of .NET Framework manifest-signing code (e.g.: [mansign.cs](https://github.com/dotnet/sign/blob/acd95606604d6ff41135556a348c4b1c521c1ef3/src/Sign.Core/Native/mansign.cs) and [mansign2.cs](https://github.com/dotnet/sign/blob/acd95606604d6ff41135556a348c4b1c521c1ef3/src/Sign.Core/Native/mansign2.cs)). We should delete all this code and move to a solution that does this for us.

See https://learn.microsoft.com/en-us/visualstudio/deployment/clickonce-deployment-dotnet?source=recommendations&view=vs-2022#mageexe.

[dotnet-mage](https://github.com/dotnet/deployment-tools/blob/main/Documentation/dotnet-mage/README.md) is the newest incarnation of mage.exe. We should talk with that team about integrating it into sign CLI.

CC @clairernovotny