Pipe character issues on Windows.

Hi,

I'm testing Rez 2.47.2 and encountering issues with pipe character handling, this time and for a change, a picture:


This is quite a problematic one, we are passing regex patterns as arguments often and it just breaks now.

I can escape them like this to some degree:

```
C:\Users\thomas>rez-env cmd -- echo "Foo^|Bar"
Foo|Bar
```

But I could not get it to work with more complex invocations unfortunately. Assuming a **my-command.bat** file which does echo its arguments, i.e. `echo %*`, in the current working directory:

```
C:\Users\thomas>rez-env cmd -- my-command --argument-a --argument-b "C:\Users\thomas\My Directory" --argument-c "\bFoo\b|Bar-Plop|John-Plop|Doe-Plop"
'Bar-Plop' is not recognized as an internal or external command,
operable program or batch file.

C:\Users\thomas>rez-env cmd -- my-command --argument-a --argument-b "C:\Users\thomas\My Directory" --argument-c "\bFoo\b^|Bar-Plop^|John-Plop^|Doe-Plop"
'Bar-Plop' is not recognized as an internal or external command,
operable program or batch file.
```

I could change `echo %*` to `echo "%*"` and it would work but if `echo` is instead a Python program which expects arguments it will break because of the double quotes as it will receive the whole line as a single argument instead of the granular arguments.

Reproduce the Windows commands using `rez-env cmd --`, the `my-command.bat` example, and a Python program that receives arguments. Trace how pipe-containing regex arguments are handled across batch and Python invocations. Done means literal pipes remain within the intended argument boundaries without command splitting or requiring quotes that collapse all arguments.

Written by the indexing model from the issue text.