curl: implement non-blocking STDIN read on Windows

curl: implement non-blocking STDIN read on Windows

Implements a seperate read thread for STDIN on Windows when curl is run
with -T/--upload-file .

This uses a similar technique to the nmap/ncat project, spawning a
seperate thread which creates a loop-back bound socket, sending STDIN
into this socket, and reading from the other end of said TCP socket in a
non-blocking way in the rest of curl.

Fixes #17451
Closes #17572