Extend proto-lens API to support serializing the protobuf JSON format

[iand675]

I needed to support JSON deserialization to the Protobuf models to integrate with a third party system with a large number of protocol buffer definitions, so it was infeasible to hand-write them.

This PR adds support for the serialization formats outlined here: https://protobuf.dev/programming-guides/proto3/#json

I also bumped some dependencies and replaced the Setup.hs codegen approach for the official protobuf types because the Setup.hs approach absolutely refused to work in the upstream Nix project. I could probably roll it back, but it's nice IMO to be able to use some of the base packages to the ecosystem without having to have the protocol buffer compiler installed.

[blackgnezdo]

Thanks for the change @iand675.

You are right that the bootstrap story is a complicated one. We pondered it quite a bit before landing on this one. The reasoning was that people who want to work with protobuf wouldn't consider it a chore to have protoc available. Keeping the generated files comes with a maintenance cost. I'd rather we limit the scope of your change to the json related features you added.

I'm also semi-blocked on ghc-source-gen ghc 9.6 support and the lack of CI support for the newer GHC versions in this project. I'd be happy if these were resolved.