convert to esm

[talentlessguy]

This PR converts the source code to ESM, potentially fixing #171, https://github.com/esm-dev/esm.sh/issues/553 and https://github.com/esm-dev/esm.sh/issues/219

todo:

• [x] passing node tests
• [ ] passing chrome tests
• [ ] passing chrome webworker tests
• [ ] passing ff tests
• [ ] pasing ff webworker tests
• [ ] passing electron tests (related https://github.com/electron/electron/pull/37535)

webworker tests are blocked by https://github.com/hugomrdias/playwright-test/issues/530

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