add in WHB helpers for PCFS/HFIO

[Mythra]

this mirrors the SD helpers but for Host File I/O, and PCFS when interacting with devkits. Most of these functions are pretty much beat for beat the same as the SD functions, the only real difference is the introduction of Well Known Host Directories which are the recommended way of referencing several 'PATHs' that a developer would commonly use without needing to hardcode paths.

[GaryOderNichts]

Thanks for creating a PR! However, instead of using the WHB file functions, stdio should be used. If you're using Aroma, you can mount the HFIO path with libmocha, allowing for access with stdio functions through a devoptab.

[Mythra]

That's fair! I mainly opened this cause it felt weird for SD card to have it, but not HFIO (given those are the only two).

I do also want to point out aroma won't run on many devices which have HFIO yet @GaryOderNichts (incase that changes your opinions), I do have it on my todo list to take a whack at properly getting aroma working on devkits, but that isn't the reality today.

Anyway if there's no interest that's okay 😊