fix(datastore): Update outbox comparison logic to fix update versioning problems

[stocaaro]

Description of changes

Outcome:

• To allow multiple partial updates, outbox checks compare all updated fields for deep equality with the returned object, but ignore extra returned fields when gating outbox _version maintenance.
• As a result, our rapid update use-cases will not drop updates

Issue #, if available

Description of how you validated changes

Validated by updating tests and testing against sample apps manaully for both Automerge and OCC usecases

Related changes

1. refactor(datastore): Move conflict resolution tests to their own file aws-amplify/amplify-js#12728
2. refactor(datastore): Refactor conflict resolution tests optimize for concise/readable aws-amplify/amplify-js#12732
3. refactor(datastore): Refactor test names and make subscription events more sample app like aws-amplify/amplify-js#12740
4. test(datastore): Add OptimisticConcurrency tests aws-amplify/amplify-js#12795
5. 🌱 fix(datastore): Update outbox comparison logic to fix update versioning problems

Checklist

• PR description included
• yarn test passes
• Tests are changed or added

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.