windows: support serial consoles for Linux guests

Add Windows serial-console support for Linux guests using both legacy serial (ttyS0) and virtio-console (hvc0).

This exposes the serial-console API on Windows and adds a Windows console bridge that translates interactive input into ANSI escape sequences. It also routes legacy COM IRQs through WHP so ttyS0 receives input, and replies to cursor-position queries for output-only consoles so guest init processes do not block waiting for terminal responses.

This fixes boot and interactive-console issues observed with Fedora Cloud and Fedora CoreOS guests.

This is built over other open Windows PRs, i'll rebase it once the previous get merged