Feature: Generate ESBuild meta files in debug mode

[vicb]

It would help us (cloudflare) to get have access to the build metadata generated by ESBuild.

One thing that could be done is to dump those to disk as [bundle_name.js].meta-file.json in debug mode.

Would that be ok to implemented it on this repo?

[conico974]

I don't see any issue with that, especially if it's in debug mode