Fixed process layer argument quoting; allows for strings with spaces.

[adamharrison]

Noticed this slight bug; when passing in arguments with strings, we don't actually escape these even if passed in array form. Should be escaped, like with Linux.

[takase1121]

As I mentioned in the relevant Discord message, there are basically 3 group of behaviors - MSVCRT, CommandLineToArgvW and vendor defined. Ultimately, most programs choose to support MSVCRT because it is similar to CommandLineToArgvW (probably compatible too!). This PR probably is implementing the MSVCRT convention too.

---

Here's a description for that from Python:

1. Arguments are delimited by white space, which is either a space or a tab.

2. A string surrounded by double quotation marks is interpreted as a single argument, regardless of white space contained within. A quoted string can be embedded in an argument.

3. A double quotation mark preceded by a backslash is interpreted as a literal double quotation mark.

4. Backslashes are interpreted literally, unless they immediately precede a double quotation mark.

5. If backslashes immediately precede a double quotation mark, every pair of backslashes is interpreted as a literal backslash. If the number of backslashes is odd, the last backslash escapes the next double quotation mark as described in rule 3.

---

Note that the definition of whitespace - \v\t are valid delimiters.

Although the MSVCRT convention allows quoting non-space arguments, this is not recommended.
While vendor-defined conventions might be incompatible with the convention, most of them do agree that non-space argument don't have be quoted. Keeping this feature would usually allow most of the simple cmd commands to run while keeping full MSVCRT compatibility. I have an example in this issue.

Other than that, a verbatim_argument option should be added.

In this mode the array will be concatenated with no escaping at all. This is the solution for node.js, but doesn't seem like it in Python. However, Python probably allows this by passing a single string rather than a list.

This option is important for aforementioned vendor-specific convention, most notably cmd. cmd simply has its own quoting convention when various flags are enabled - think /s and by providing verbatim_argument we won't interfere with possible escaping by the user.

[adamharrison]

Sure; instead of verbatim argument; we could also simply allow for a string to be passed as well, instead of a table. Would probably be me natural.

[takase1121]

I'd agree, but if we provide a string in POSIX platforms I don't know how it would be handled. I would assume Python simply uses shlex to convert it into an argument array.

EDIT: nevermind, Python simply uses it as argv[0], we're all good.

[adamharrison]

OK, added in the ability to specify a string; just argv[0] on POSIX; literal string on windows. Checked with python; behaviour is identical.

[jgmdev]

Tested changes on windows and everything is working normally so merging