[RFC] "http-types" breakage / additions / rework

If breaking http-types on a new major version, for each reverse dep that uses it:

1. they have set strict version bounds, and nothing happens; the maintainer updates the dep whenever
2. they don’t have strict version bounds, and:
   1. break forever, or
   2. break until a Hackage trustee revises the package metadata, or
   3. break until the original maintainer gets around to it, or
   4. break until a new maintainer appears and saves the day

The sentiment of “they knew what they were getting in to, I say, let them crash” is not really accurate: it’s going to cumulatively create a lot of work for people who weren’t the original villains who deigned to not put <X on their http-types dep, but who just want to not have a non-broken package.

With that in mind I would prefer to just have a new package http-types-but-better that be can migrated to; in the worst case scenario the original http-types gets increasingly loud and desperate deprecation notices, and there’s some more impetus for the Hackage UI to be improved so that that sort of thing is more obvious. Or it just remains frozen in time because, for whatever its design and performance pitfalls, it’s a stable design that doesn’t “need” change.