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.
This implements end-to-end encryption between the end-device and
end-application. The encrypted AppSKey or SessionKeyID is forwarded to
the end-application which should be able to decrypt or request the
AppSKey to decrypt the uplink payload. As well the end-application will
be able to enqueue encrypted application payloads.
Using this mechanism, ChirpStack will never have access to the uplink
and downlink application-payloads.
