1. Add `:event_handler` app option. It is a process that will receive
the app events, the `:open_app`, `{:open_url, url}`, and
`{:open_file, path}` messages.
2. Add `AppBuilder.init/0`. This reads the `APP_BUILDER_INPUT` env
variable which contains the app event the release was started with.
3. Use <https://github.com/wojtekmach/otp/tree/wm-WX_MACOS_NON_GUI_APP>
branch which contains wx fix that hasn't been merged yet.
* Adjust stop reasons for server processes
* Update lib/livebook/unique_task.ex
Co-authored-by: José Valim <jose.valim@dashbit.co>
Co-authored-by: José Valim <jose.valim@dashbit.co>