All these files can be generated using the `make api` command and there
is no real need to commit these into the repo. Only the api/go files
need to be comitted of how the Go import system works.
This also updates the Rust, Go, JS and gRPC-web (JS) code generation and
UI build to use the nix-shell environment instead of using Docker.
With the update to diesel 2.0.0-rc0, it is now possible to cross-compile
without emulation. Note that during each (cross)compile, we have to
install libpq-dev for the target platform, as only one version can be
installed at a time (e.g. libpq-dev:amd64 conflicts with libpq-dev:armhf).
