chore: omit previousResult, lastCompleteResult from options/result

[alessbell]

After discussing with @benjamn today, it was determined previousResult can be omitted from UseFragmentOptions.

In documenting UseFragmentResult in PR #10099, it seems we may be able to omit previousResult and lastCompleteResult from the result type as well. I've done some logging in our tests and don't see where they're used, but happy to add them back if they are.

Checklist:

• If this PR is a new feature, please reference an issue where a consensus about the design was reached (not necessary for small changes)
• Make sure all of the significant new logic is covered by tests