Bindings for FormData

[yawaramin]

I took a look at https://developer.mozilla.org/en-US/docs/Web/API/FormData and it seems binding this will involve writing some tricky bindings like iterators, Blobs, and so on.

@glennsl do you have any suggestions for this? Or maybe I can play around with it a bit and see what I come up with.

[glennsl]

Yeah, that's a tricky one. There's been some attempt at adding it to bs-fetch too: melange-community/melange-fetch#14

At the very least I think the formData and blob types should be added to Dom in bs-platform, to avoid needing bs-webapi as a dependency of bs-fetch for eaxmple. (And there's a few more types here that could be brought over then too, like image).

I also think Bob had some thoughts about iterator support in BuckleScript a few years ago. I don't know if he's thought any more about that, but might be worth asking.