Add Windows process listing command

[caomengxuan666]

Fixes #54.

Adds a small native Windows ps implementation under deps/ntps. It lists running processes using the Toolhelp snapshot APIs and supports a focused set of common options:

• ps, ps -A, ps -e
• BSD-style ps ax / ps aux
• -p / --pid PID filtering
• --ppid parent PID filtering
• -o / --format for supported columns: pid, ppid, comm / command / args, nlwp, pri
• --no-headers

This also adds ps to the PowerShell integration rewrite list, so interactive bare ps can be routed to ps.cmd like the other coreutils commands. Get-Command ps may still show the PowerShell alias, matching the existing README caveat for other rewritten commands.

This is intended as a Windows-specific convenience command to pair with kill, not as a full procps replacement.

Verified with:

• cargo test --target x86_64-pc-windows-msvc -p uu_ps
• cargo check --target x86_64-pc-windows-msvc --bin coreutils
• cargo build --target x86_64-pc-windows-msvc
• cargo test --target x86_64-pc-windows-msvc
• smoke-tested coreutils.exe --list, ps, ps -A, ps -e, ps aux, ps -p, ps --ppid, ps -o, ps --no-headers, and ps --help