fix: json schema bugfixes

[Marsup]

Hi @AbdelrahmanHafez.

As your PR is too big a wall to review, I allowed myself to cherry-pick some of your work, focusing first on fixing the parts that are already present in the latest release. I don't know yet how we can cut the rest of it, but this feels like a good 1st step.

I tried to keep attribution where I could, but your name may appear on commits that don't strictly reflect what you did. Let me know if it's OK.

I hope the conflicts will be manageable.

[AbdelrahmanHafez]

Hi @Marsup, sounds good overall (attribution, and cutting the other PR).

Hopefully merging this also shrinks the diff on the bigger PR. After that I'm happy to split the rest into subsets of features, and you can tell me which ones are actually worth it for Joi given the maintenance cost (or cherry-pick them yourself as you did here).

If that's the direction you have in mind, I'll open smaller PRs, just a heads up that I'll be slow to respond over the next few weeks.