Support Bundling with esbuild

[r-token]

As mentioned in #18, esbuild fails to bundle this library (and other packages like hypercast-podcore-next that use this library) due to an issue in the batch dependency. This increases package/deployment sizes considerably.

I have forked the Batch repo, implemented the workaround, and published it as a standalone package scoped to my username. Those changes have been pulled into this repo. It should not introduce any breaking changes downstream.

The workaround implemented in my fork of the Batch repo simply changes this:

try {
  var EventEmitter = require('events').EventEmitter;
  if (!EventEmitter) throw new Error();
} catch (err) {
  var Emitter = require('emitter');
}

to this:

try {
  var EventEmitter = require('events').EventEmitter;
  if (!EventEmitter) throw new Error();
} catch (err) {
  try {
    var Emitter = require('emitter');
  } catch (err) {
    console.error('Unable to create an emitter')
    throw err
  }
}

You'll notice I now wrap the var Emitter = require('emitter'); line in a try/catch so that eslint doesn't complain when it sees that that emitter package does not exist and cannot resolve it. That is the extent of the changes.

If you can think of a better solution than using this forked version of Batch, I'm all for it. The main package hasn't been updated since April of 2021 though, so I don't think there's much risk in forking it and falling behind. Previous attempts by others to give it better bundler support have been declined by the maintainer.

Closes #18

[r-token]

Don't merge this quite yet even if you're cool with it. I've submitted an issue and associated PR to the actual Batch repo that has already gotten the attention of the maintainer, so maybe we'll be able to get this fixed in the actual repo and use that.

[r-token]

Update: they want to merge this in, hoping to do it either today or tomorrow.

Relevant comment from the maintainer: visionmedia/batch#43 (comment)

[r-token]

My updates were merged into the main Batch repo with this commit. So Batch can now be built with esbuild!

All we need to do here is install the latest version of Batch and cut a new release of little-media-box that the serverless repo can update to.

[r-token]

These changes were committed to GitHub via this commit.

I've updated little-media-box's package.json via this PR to use the latest version of Batch from GitHub, which includes these changes. That will allow us to build LMB with esbuild, drastically reducing package size.

I believe this is now ready to be merged and a new release can be cut @agrathwohl.