Include erlang ffi modules on .app file for releases to work with gleam apps

[LostKobrakai]

gleam new repro
cd repro
gleam export erlang-shipment 
cat build/erlang-shipment/gleam_stdlib/ebin/gleam_stdlib.app

The modules list is missing gleam_stdlib for being an erlang ffi module.

Same problem applies to hex tarballs *.app.src files.

[lpil]

Thank you.

[lawik]

Smells like Nerves support.

[lpil]

High priority it is

[LostKobrakai]

Leaving some notes from me digging through the codebase:

It seems like compiler-cli/templates/gleam@@compile.erl would need to be updated to not just return ok/error, but also the module names of successfully compiled modules. BeamCompiler.compile would then return that to PackageCompiler.perform_erlang_codegen, which after some reordering could then write an app file containing both gleam sourced modules as well as erlang/elixir ffi sourced modules.