feat: HTTP Snippet client for Node samples

[erunion]

🧰 What's being changed?

This creates a new package, httpsnippet-client-api, that allows for the creation of Node code samples, via httpsnippet, for the api module.

Using the new plugin architecture I've PR'd to HTTP Snippet, we can load in this new client with the following lines:

const client = require('httpsnippet-client-api');
HTTPSnippet.addTargetClient('node', client);

And once it's loaded, you can use HTTP Snippet as you would any other target+client combination:

const snippet = new HTTPSnippet(harObject);
console.log(
  snippet.convert('node', 'api', { 
    apiDefinitionPath: 'https://example.com/openapi.json'
  })
);

🧪 Testing

Since the unit tests for httpsnippet are pretty ingrained into that repository, I've extracted the target-related tests and all their fixtures to facilitate testing this module. As such since we're pulling in code I didn't write, I am also pulling in their license.

Ideally this code/plugin infrastructure would be available in a generator package like generator-eslint, but that is way out of scope for this right now. Maybe once the plugin PR is accepted into httpsnippet, and we start building additional api clients for different languages, we can work on something there. Until then, yolo.

🗳 Checklist

💡 If answering yes to any of the following, include additional info, before/after links, screenshots, etc. where appropriate!

• 🆕 I'm adding something new!
• 🐛 I'm fixing a bug!

[julshotal]

Was on call while this was being worked on, tests are very concise and produced the correct output