Add Windows ARM64 support

[dennisameling]

VS Code is available for Windows ARM64 natively, which results in great performance. However, CodeHelper.exe is still x86, which uses emulation on Windows ARM64, resulting in slower performance.

It'd be great if CodeHelper.exe could be made available for Windows ARM64 natively. Currently, this module targets .NET Framework 4.5, which doesn't support ARM64. Therefore, it would first need to be upgraded to .NET 5.

I'm happy to help with upgrading if the team would like that, and I have some first work done in https://github.com/dennisameling/vscode-filewatcher-windows/tree/dotnet-5, which compiles just fine. The team would need to decide which deployment model they prefer (self-contained or framework-dependent), which may have a significant impact on binary size.

CC @joaomoreno who mentioned the wish for native ARM64 binaries in microsoft/vscode#98587

[joaomoreno]

Yeah this would be cool to have and likely easy as well.

[bpasero]

Yeah maybe, maybe not. I have had (and still have) my doubts that shipping 3 different file watching solutions (this one, chokidar, nsfw) is scaling well for VSCode for a long time and really want a single unifying solution for file watching in 1 library that is supporting all platforms VSCode supports.

The more pressure we get to change this, the better imho. So I would rather invest energy into that 1 library for all platforms than continuing what we do now.