Configure zip.js with pako workers

[ebogo1]

Fixes CesiumGS/3d-tiles-validator#215.
Fixes CesiumGS/gltf-pipeline#603.
Fixes CesiumGS/obj2gltf#266.

This should also make CesiumJS work with Node 16.

All the above issues came from the configureWebWorker function, which is included in most versions of zip.js except for zip-no-worker.js. This version of zip.js depends on external inflate and deflate workers, which luckily we already have from pako. To put them in a location that's accessible in built/packaged CesiumJS, I added some steps to the prepare task to copy the required files from node_modules.

I think this is merge-able as is, but it'd be nice to get a single place to run zip.configure({ ... }). In 1ff47b6 I tried doing this with Source/Core/zipPakoConfig.js, but this did not work with built versions of Cesium and I haven't figured out why yet.

This does not fix the issues opened in CesiumJS about zip.js regressions in 1.85, but for now I believe all of those are related to webpack 4 not working with worker imports out of the box (webpack 5 does).

[cesium-concierge]

Thanks for the pull request @ebogo1!

• ✔️ Signed CLA found.
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  • If this change updates the public API in any way, please add a bullet point to CHANGES.md.
• ❔ Changes to third party files were made.
  • Looks like a file in one of our ThirdParty folders (ThirdParty/, Source/ThirdParty/) has been added or modified. Please verify that it has a section in LICENSE.md and that its license information is up to date with this new version.
• ❔ Unit tests were not updated.
  • Make sure you've updated tests to reflect your changes, added tests for any new code, and ran the code coverage tool.

Reviewers, don't forget to make sure that:

• Cesium Viewer works.
• Works in 2D/CV.
• Works (or fails gracefully) in IE11.

[lilleyse]

I confirmed that the KMZ related sandcastles work and unit tests pass locally, both in local development and with the built version. I also confirmed that obj2gltf and other node libraries that use the cesium package work in Node 16 again. No notable change in the built Cesium.js size.

I think this is merge-able as is, but it'd be nice to get a single place to run zip.configure({ ... }). In 1ff47b6 I tried doing this with Source/Core/zipPakoConfig.js, but this did not work with built versions of Cesium and I haven't figured out why yet.

I'm ok with the current approach, at this point it's better to merge and move on to other things. @ebogo1 could you start a 1.86.1 section in CHANGES.md and add a note that this fixes a regression in the cesium npm package when using Node 16.

[mramato]

I already spoke to @ebogo1 about this offline but having a single configuration point should be trivial by just creating a single Core/zip that does a one time configuration. Then clients import that instead of the third party directly. That's exactly how knockout works as well and other libraries throughout our code bases that have configuration that needs to be done before use.

[lilleyse]

Merging, @ebogo1 opened #9863 for future cleanup here