Readable JS assets Plugin: Fix webpack 5 support

[walbo]

Description

In webpack v5 Compilation.chunks and Chunk.files changed from arrays to sets. See https://webpack.js.org/blog/2020-10-10-webpack-5-release/#arrays-to-sets

Support both v4 and v5 by making sure we work with arrays (converting the set to array for v5) when generating the files list.

How has this been tested?

Tested the plugin both in webpack v4 and v5.

Types of changes

Bug fix

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• I've tested my changes with keyboard and screen readers.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR (please manually search all *.native.js files for terms that need renaming or removal).

[jsnajdr]

Looks good 👍 As a personal style preference, I think calling Array.from( setOrArray ) would be a bit nicer.

[walbo]

Looks good 👍 As a personal style preference, I think calling Array.from( setOrArray ) would be a bit nicer.

Yes. Personal preference. Seem like Array.from are the preferred method when looking at the codebase. I'll update the PR.