[Process API] Quoting enhancements

[takase1121]

This PR avoids quoting strings if it does not have newlines, as well as adding SDL_PROP_PROCESS_CREATE_CMDLINE_STRING as an alternative.

Description

This issue was described in #12945.
This PR offers two solutions:

1. SDL will not quote strings unless it needs to (if it includes whitespaces).
2. SDL_CreateProcessWithProperties will accept another property called SDL_PROP_PROCESS_CREATE_CMDLINE_STRING, which lets library users pass an escaped command line to CreateProcess directly.
   This is useful for SDL wrappers that needed to allow users to call old executables that has their own command line escaping.

Take cmd.exe /S /C as example: /S will strip first and last double quotes from the command line, after /C itself.

Method	Passed to CreateProcess	Passed to batch processing
SDL {"cmd.exe", "/s", "/c", "echo \"hello world\"", NULL}	cmd.exe /s /c "echo \"hello world\""	echo \"hello world\"
Raw string cmd.exe /s /c "echo "hello world""	cmd.exe /s /c "echo "hello world""	echo "hello world"

The code should not interfere with #10857.

Existing Issue(s)

Fixes #12945.

[madebr]

Having this option does not feel very safe to me.
What does it allow which the current behavior does not?

[takase1121]

Unfortunately yes. This is an option that you shouldn't use unless you know what you're doing, but is needed because Windows have 3 main types of argument escaping (UCRT, CommandLineToArgvW, and cmd.exe) which are slightly different to each other and can cause issues. See my examples in the PR comment about cmd.exe /s /c, which is legitimately a good way to use cmd.exe and to avoid lots of escaping. If not, you'll have to escape for both cmd.exe's command line parsing AND batch processing, which eats up precious command line space (note that in Windows the command-line is 65535 characters long, and batch parsing only takes around 8000 characters, including escape).

Other language runtimes have this features as well:

• node.js(windowsVerbatimArguments):https://nodejs.org/api/child_process.html#child_processexecfilefile-args-options-callback
• Python: https://github.com/python/cpython/blob/af5799f3056b0eee61fc09587633500a3690e67e/Lib/subprocess.py#L1461

As a library, I think its better to focus towards functionality - the warning is there, so you will use that option at your own risk.

[takase1121]

Another way could be adding a callback to allow user to customize how the arguments are escaped - like join_cmdline. That'll probably scare away users that didn't have a solid justification for using this feature.

[takase1121]

Just for context: command-line parsing is delegated to the callee application, often done as a part of libc startup code. Thus, it can't fail because of "syntax errors", so they're just propagated to the parsed argc and argv themselves.

cmd.exe inherited it's parsing from DOS, and MSVCRT and UCRT applications all have slightly different ways of parsing the command line. This means applications compiled on different compilers (e.g. MINGW64 and UCRT64) could use different schemes. The SDL escaping is good for UCRT and probably works for MSVCRT, but can fail for cmd.exe.