Enable unawaited_futures

[PIG208]

Fixes part of #731

[PIG208]

TODO: TestGlobalStore's doInsertAccount implementation has a race condition for checking the invariants. Concurrently adding accounts allows you to bypass the check.

[chrisbobbe]

This sounds helpful!! It looks like we have an issue for it: #731 🙂

[PIG208]

This is stacked on top of #937.

[PIG208]

This is stacked on top of #970 (dialog [nfc]: Wrap showErrorDialog's return value).

The PR is mostly small commits for refactors in a limited scope.

[gnprice]

Other than api/core_test.dart as in the comment above (for which see #985), these changes all generally look like improvements to the code. And this is a PR that I expect would gather frequent conflicts as we merge other changes.

So I'd like to get this completed, even though as discussed on #731 we won't currently be able to enable the companion lint rule discarded_futures.

[chrisbobbe]

So I'd like to get this completed

To help this along, I've just reviewed #970; over to you, Greg, for integration review on that.

[PIG208]

Updated the PR by cherry picking #970 and #985 and cleaning up some commit messages.

(The CI failure comes from #985)

[chrisbobbe]

Thanks! LGTM, except the commit that enables unawaited_futures should mention #731. As discussed on that issue, it sounds like we won't be enabling that other rule discarded_futures, so maybe the commit should say Fixes: ?

[PIG208]

I think we should keep #731 open because there is still some chance that we can use that rule, but not in the near future. Mentioning it in the commit message seems fine.

[PIG208]

Thanks for the review! Updated the PR and fixed some more errors that appeared after rebasing (and applied #731)

[gnprice]

Thanks for the revision! All looks good; merging, with one NFC commit on top:

1aef86814 api test [nfc]: Simplify some unawaited checks