FedURIs, until now, have been requiring HTTPS, and no port number, and DNS
internet domain names. This works just fine on the forge fediverse, but it
makes local dev builds much less useful.
This patch introduces URI types that have a type tag specifying one of 2 modes:
- `Dev`: Works with URIs like `http://localhost:3000/s/fr33`
- `Fed`: Works with URIs like `https://dev.community/s/fr33`
This should allow even to run multiple federating instances for development,
without needing TLS or reverse proxies or editing the hosts files or anything
like that.
Until now, there were some simple host checks when verifying the HTTP sig,
meant to forbid hosts that are IP addresses, local hosts, and maybe other weird
cases. These checks moved to Network.FedURI, so now FedURIs in general aren't
allowed to have such hosts. The host type is still `Text` though, for now.
Using a dedicated type allows to record in the type the guarantees that we
provide, such as scheme being HTTPS and authority being present. Allows to
replace ugly `fromJust` and such with direct field access.
