refactor(otlp-transformer): generate and export esm protos

[overbalance]

Which problem is this PR solving?

The ESM version of otlp-transformer includes ./experimental/packages/otlp-transformer/src/generated/root.js containing the compiled output of the protos. This is generated by ./scripts/generate-protos.js in CommonJS format.

// root.js
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var $protobuf = require("protobufjs/minimal");
....

Short description of the changes

This PR generates an additional ESM file ./experimental/packages/otlp-transformer/src/generated/root.mjs and copies it into the build/esnext and build/esm folders as root.js.

// root.mjs
import * as $protobuf from "protobufjs/minimal";
....

I know protobufjs/minimal is still CommonJS, but figured we should modernize what we can on our end.

Type of change

I marked as refactor since it's not providing new functionality. Please advise if I should change it.

How Has This Been Tested?

npm run compile then check the build folders for the appropriate file.

Checklist:

• Followed the style guidelines of this project

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.17%. Comparing base (3dc8979) to head (4495b05).
⚠️ Report is 21 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5925   +/-   ##
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  Coverage   95.17%   95.17%           
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  Files         316      316           
  Lines        8521     8521           
  Branches     1763     1763           
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  Hits         8110     8110           
  Misses        411      411           

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[pichlermarc]

Thanks! Approach overall idea is sound and works when the files are where they are supposed to be 🙂 I tested it using rollup and Node.js since Node.js always falls back to CJS if there's no "type": "module" entry.

However, the way the script is set up right now it does not actually copy it to the correct location when running npm run compile from the top-level.

[pichlermarc]

The top-level compile script actually does not call this one - the result of that is that the published package won't have the generated ESM copied to the right locations, and the CJS one will be included.

(To reproduce: run npm run compile from the top-level of the repo and inspect the experimental/otlp-transformer/build/esm/generated/root.js)

[pichlermarc]

using cp will not work for devs on windows, I think we need to consider an alternative here
(if something is not working for windows devs it usually comes up really quickly after merging a PR 😅)

[overbalance]

Oh. I'll remember that in the future 😎

[overbalance]

Closing in favor of choosing a real ESM replacement.