implement std.Progress IPC for Windows

[andrewrk]

Extracted from #20059.

Currently, on Windows, std.Progress is implemented for the root process that owns the terminal, however it is not able to collect progress information from the child processes that it spawns.

This issue can be closed when child processes using std.Progress on Windows communicate their progress to parent processes.

A simple way to test this would be adapting this example to also work on Windows:

https://gist.github.com/andrewrk/b22b4f663cef6b4672d7097de95ea343

For POSIX systems this is implemented by a dedicated pipe file descriptor that is passed from parent to child, much like stdio streams. It should be possible to do something equivalent on Windows.

[mlugg]

Another easy way to test this is simply to use the Zig build system to compile some Zig code. Once the build is running, you should see a bunch of progress output from the Zig compiler about individual declarations being analyzed / codegenned / linked, but on Windows today you'll just see one progress node representing the entire Compile step: