feat: calculate emissions from page speed results

[jonoliver]

• Add function to calculate emissions from Google PageSpeed results
• Install @tgwf/co2
• Add bundle script to bundle the above dependency for use in the browser

TODO

• Integrate with feat: page speed fetch request #9
• Remove temp data
• Determine which model to use (OneByte model or Sustainable Web Design (SWD) model)

Validation

1. npm run build
2. Load the extension in the browser
3. Navigate to https://sparkbox.com/ and open the devtools js console
4. Open the extension and click "Analyze this page"
5. Wait for the page scan to complete. Verify that you see the calculation results in the js console: Emissions Calculation Results: {bytesTransferred: 1899035, totalCO2: 0.28143698699999997}

[github-actions]

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[jonoliver]

We didn't have anything bundling our js for the browser, and this is the first time that we're importing a 3rd party npm package @tgwf/co, e.g:
import { co2 } from "@tgwf/co2";

Since deps from node_modules weren't being bundled, trying to import resulted in this error when running the extension in the browser: TypeError: Failed to resolve module specifier "@tgwf/co2".

This is kind of a quick and dirty solution that just bundles the carbon calculator with the underlying dependency. We could probably improve this by bundling each entry point js file along with their underlying deps, but that's bigger than the scope of this PR.