Expand Fireproofing to include Local Storage and IndexedDB

[samsymons]

Task/Issue URL: https://app.asana.com/0/1177771139624306/1200042850887108/f
Tech Design URL:
CC:

Description:

This PR updates the Fireproofing feature to preserve Local Storage and IndexedDB. It only preserves IndexedDB on macOS 12.2+, as earlier versions have a privacy flaw related to that feature (see the comment in the code for more).

Steps to test this PR:

Testing Fireproof sites:

1. Sign into a site that stores data in Local Storage or IndexedDB; https://numer.ai/ is a good example, which uses Local Storage for its auth token
2. Don't Fireproof it, and then use the Fire button; check that you are signed out
3. Visit the site again, log in, Fireproof it, and burn once more
4. Check that you were not signed out

Testing non-Fireproof sites:

1. Visit some sites that aren't Fireproof, as well as some that are Fireproof
2. Add a breakpoint in removeLocalStorageAndIndexedDBForNonFireproofDomains
3. Use the Fire button and check that the right records are removed

Testing checklist:

• Test with Release configuration

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Internal references:

Software Engineering Expectations
Technical Design Template
When ready for review, remember to post the PR in MM

[brindy]

LGTM!

Didn't test on 12.2 but commented out the available check and it left indexed db database in place when burning.

[samsymons]

@brindy So sorry – I realized belatedly that the additional step I added to remove Local Storage and IndexedDB for domains that aren't Fireproof hadn't been pushed yet (without that change, all domains would have had this data retained), so I've done that and added a bit of bonus variable/function renaming to clear things up. Would you be able to take another look? 🙏

[brindy]

Make sense! LGTM!