feat(cli): expose a function to kill dev child

[amrbashir]

What kind of change does this PR introduce?

• Bugfix
• Feature
• Docs
• New Binding issue #___
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change?

• Yes, and the changes were approved in issue #___
• No

Checklist

• When resolving issues, they are referenced in the PR's title (e.g fix: remove a typo, closes #___, #___)
• A change file is added if any packages will require a version bump due to this PR per the instructions in the readme.
• I have added a convincing reason for adding this feature, if necessary

Other information

Sometimes while using the cli.js API from a JS script, a zombie process is left after killing the JS script using ctrl+c. I can't reproduce it reliably but having an API to kill the dev app process, the script could execute it upon exit:

process.on('SIGTERM', () => killDevApp());
process.on('exit', () => killDevApp());

[lucasfernog]

I think we should try to do it on our end instead. Or maybe the JS script could just listen to ctrl+c and kill the CLI process manually?

[amrbashir]

I think we should try to do it on our end instead.

We could do that in cli.js but we'd still need to expose the function through NAPI

Or maybe the JS script could just listen to ctrl+c and kill the CLI process manually?

Again, we still need to expose a function to kill the process or at least the PID.

[lucasfernog]

I still couldn't reproduce the issue :( I actually wanted to listen to the signal on the Rust code and let it handle it instead.

[amrbashir]

Yeah I can't really reproduce it reliably but I think it happens only after you triggered the CLI hot-reload at least once or twice.