Make named pipe configuration less error prone

[Darksonn]

The current design of the named pipe builder resulted in CVE-2023-22466. It should be refactored to make this kind of mistake impossible.

Refs: #5336

[mhils]

@Darksonn: is 09a37c7 the type of refactoring you have in mind? :)

[Darksonn]

Yeah, that looks reasonable, although we might want to make the same change to the open mode.

[mhils]

Excellent. I've implemented the same changes for open_mode/desired_access and removed the bool_flag macro in 658c3f8. That's currently sitting on top of #5350 though, so unless y'all have strong opinions here I will wait with a PR until #5350 is in. :)

[Darksonn]

Sorry that I forgot about your PR. Do you want to submit the other commit as a PR?

[mhils]

No worries and thanks for getting to it! I've rebased the patch from above and opened #5477. :)