Implement proper Google provider using its first-class API

[felixarntz]

Fixes #106

Replaces #152 (which was accidentally using the protected feature/* branch prefix)

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[felixarntz]

@JasonTheAdams Can you please add #152 (comment) here?

[felixarntz]

@JasonTheAdams 638a0ac addresses your feedback in #152 (comment). The same wording was already present in several other places, so I updated it everywhere.

[felixarntz]

@JasonTheAdams Can you please give this a re-review so we can get it merged? No changes compared to #152, other than the extra commit above.

[JasonTheAdams]

This is great! LGTM! 🚀

I did push my typing refactor, so let me know if you have any thoughts on that before we merge.