build: fix cmake builds not working on windows

[scarf005]

Purpose of change (The Why)

• prereq of build: write visual studio + cmake guide #8062

Describe the solution (The How)

can't just install gettext with vcpkg because of microsoft/vcpkg#8272
uses pre-compiled binaries from https://github.com/mlocati/gettext-iconv-windows instead

Testing

worked on VM

2026-02-08_10-51-10.mp4

[AzmodiusX]

I still get errors for the json formatter if I don't set the generator to Ninja.
Disabling that just has another error, and so on.
Any reason we don't just use the Ninja generator?

[AzmodiusX]

Additionally, I had to re-do many cmake setup steps, so this likely won't be drag and drop for current windows devs.
Should be fine though, the actual steps aren't complex.

[AzmodiusX]

You know, I think my setup is reverse broken.
I managed to make everything work without this PR (or Ninja).
If I test again, I'm also using a VM.
Edit: or not
I hate windows too friend

Ok, so as not to spam, edit:
It now compiles without this PR, but requires Ninja generator
But only after the cmake command is run with Visual Studio 17 2022 as the generator (maybe?)
I am hate

[chaosvolt]

Above issues should be addressed before it's ready for merging.

[AzmodiusX]

Assuming they exist and that my windows install isn't somehow more cursed than yours.