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 curl#17451
Closes curl#17572

Replace `_beginthreadex()` C runtime calls with native win32 API
`CreateThread()`. The latter was already used in `src/tool_doswin.c`
and in UWP and Windows CE builds before this patch. After this patch
all Windows flavors use it. To drop PP logic and simplify code.

While working on this it turned out that `src/tool_doswin.c` calls
`TerminateThread()`, which isn't recommended by the documentation,
except for "the most extreme cases". This patch makes no attempt
to change that code.
Ref: 9a26633 #17572
Ref: https://learn.microsoft.com/windows/win32/api/processthreadsapi/nf-processthreadsapi-terminatethread

Also:
- use `WaitForSingleObjectEx()` on all desktop Windows.
  Ref: 4be80d5
  Ref: https://sourceforge.net/p/curl/feature-requests/82/
  Ref: https://learn.microsoft.com/windows/win32/api/synchapi/nf-synchapi-waitforsingleobjectex
- tests: drop redundant casts.
- lib3207: fix to not rely on thread macros when building without thread
  support.

Assisted-by: Jay Satiro
Assisted-by: Marcel Raad
Assisted-by: Michał Petryka
Follow-up to 3802910 #11625

Closes #18451

Replace `WSASocketW()` with `CURL_SOCKET()`. Also replace a call
to `socketclose()` with `sclose()`. According to a comment,
`socketclose()` was chosen to silence test 1498 (and 2300) reporting
`MEMORY FAILURE`. These reports were accurate, and were caused by
calling `WSASocketW()` instead of `socket()` (now `CURL_SOCKET()`).

This also fixes the curl `sclose()` call on an error branch, which is
now correctly paired with a curl socket open. The mismatched open/close
calls caused an issue in TrackMemory-enabled (aka `CURLDEBUG`) builds.

Docs confirm that `socket()` is defaulting to overlapped I/O, matching
the replaced `WSASocketW()` call:
https://learn.microsoft.com/windows/win32/api/winsock2/nf-winsock2-socket#remarks

Also:
- checksrc: ban `WSASocket*()` functions.
- report `SOCKERRNO` instead of `GetLastError()` for socket calls,
  to match the rest of the codebase.

Follow-up to 9a26633 #17572

Closes #18633

- fix duplicate space in error message (UWP)

Follow-up to 9a26633 curl#17572

Prior to this patch, some Windows logic, including a Windows-specific
warning message was compiled in for all platforms.

Also:
- fix double space in warning message on UWP.
- formatting.

Follow-up to 9a26633 #17572

Closes #20213

Follow-up to 9a26633 curl#17572

For general readability. Also to match the rest of the source code.

- `SOCKADDR` -> `struct sockaddr`
- `SOCKADDR_IN` -> `struct sockaddr_in`
- `== SOCKET_ERROR` -> `== -1` or silent `!= 0`

Follow-up to 9a26633 #17572

Closes #20452

Follow-up to a81ab3e curl#20452
Follow-up to 9a26633 curl#17572

Follow-up to a81ab3e curl#20452
Follow-up to 9a26633 curl#17572

For general readability. Also to match the rest of the source code.

- bump `send()` result type from `int` to `ssize_t`.
- fix an `int` to be `curl_socklen_t`.
- `.S_un.S_addr` -> `.s_addr`.
- `SD_RECEIVE` -> `SHUT_RD`.
- `SD_SEND` -> `SHUT_WR`.

Follow-up to a81ab3e #20452
Follow-up to 9a26633 #17572

Closes #20457

Follow-up to 9a26633 curl#17572

Follow-up to 9a26633 curl#17572

Also:
- checksrc: ban `send` and `recv`, as documented in `CODE_STYLE.md`.

Follow-up to 9a26633 #17572
Ref: a585cc3 #20097
Ref: #20441

Closes #20459