This PR mostly deals with building obelisk/lib libraries via ghc(js) 9.8.2 + 9.10.1, and not integrating new js backend into default.nix, yet. I intend to create a test app and based on that app recreate default.nix that uses haskell.nix instead of nixpkgs/reflex-platform (may backport some things into reflex-platform). Still, it passes selftest and is backwards compatible with previous ghc/ghcjs setup.

Built using haskell.nix/cabal-install.
Here's a "hello world" example on how to build a project depending on this version of obelisk: https://github.com/ymeister/obelisk-example

Needs:

• Build with ghc 9.10.1 reflex-frp/reflex-fsnotify#10
• Build with ghc(js) 9.8.2 + 9.10.1 reflex-frp/reflex-dom#474
• Build with ghc(js) 9.8.2 + 9.10.1 reflex-frp/reflex#502
• Build with ghc(js) 9.8.2 + 9.10.1 reflex-frp/patch#56

I have:

• Based work on latest develop branch
• Followed the contribution guide
• Looked for lint in my changes with hlint . (lint found code you did not write can be left alone)
• Run the test suite: $(nix-build -A selftest --no-out-link)
• Updated the changelog
• (Optional) Run CI tests locally: nix-build release.nix -A build.x86_64-linux --no-out-link (or x86_64-darwin on macOS)