Hello!

I noticed that there are currently two very similar functions for fetching
json data; `json-fetch' in (guix import json) and `json-fetch*' in (guix
import github).

Some things I noticed:
- Dealing with http error codes seems to be a bit more robust in
`json-fetch*'.
- Making sure that (compliant) servers give responses in the proper format
seems more robust in `json-fetch' due to using Accept headers.
- Dealing with the fact that json responses are technically allowed to be
lists of objects, which `json-fetch' does not handle gracefully.

For this issue specifically, would it make sense to combine the two
definitions into a more general one?

My more general concern would be on how we can prevent bug fixes only being
applied to one of several nearly identical functions. IOW, should we try to
prevent situations like this from arising, or is it okay if we somehow make
sure that fixes should be applied to both locations?

-- 
Jelle