gh-59705: Implement _thread.set_name() on Windows

[vstinner]

Implement set_name() with SetThreadDescription() and _get_name() with GetThreadDescription(). If SetThreadDescription() or GetThreadDescription() is not available in kernelbase.dll, delete the method when the _thread module is imported.

Truncate the thread name to an arbitrary limit of 64 characters.

set_name() raises ValueError if the name contains an embedded null character.

• Issue: Python should support exporting thread names to the OS #59705

[vstinner]

Code based on @eryksun's code: #59705 (comment). Differences with his code:

• I only look for functions in kernelbase.dll, not in api-ms-win-core-processthreads-l1-1-3.dll (kernel32).
• set_name() doesn't ignore E_NOTIMPL. That's fine since the threading module ignores any OSError. If Python is run on Windows older than 10.0.14393 (1607), set_name() failure would just be ignored silently.
• I used the PyUnicode API to convert to/from wchar_t*.

Truncate the thread name to an arbitrary limit of 64 characters.

I copied this limit from @eryksun's code. Maybe it can be extended to 32766 characters?

set_name() raises ValueError if the name contains an embedded null character.

If it's a blocker issue, I can write the code differently to truncate to the first null character instead.

[vstinner]

cc @serhiy-storchaka

[vstinner]

set_name() raises ValueError if the name contains an embedded null character.

I misunderstood the code, in fact, the name is truncated at the first null character (ValueError is not raised): same behavior than Linux/macOS/FreeBSD/etc.