refactor(datastore): Move conflict resolution tests to their own file

[stocaaro]

Description of changes

Outcome:

• The sequence / conflict resolution testing is separated out from other connection testing
• There are no changes in this aside from migrating the tests and the before / after blocks needed to keep them working.

Description of how you validated changes

This change is a pure refactor of test code. It is validated as correct since all tests continue to pass.

Related changes

1. 🌱 refactor(datastore): Move conflict resolution tests to their own file
2. refactor(datastore): Refactor conflict resolution tests optimize for concise/readable #12732
3. refactor(datastore): Refactor test names and make subscription events more sample app like #12740
4. test(datastore): Add OptimisticConcurrency tests #12795
5. fix(datastore): Update outbox comparison logic to fix update versioning problems stocaaro/amplify-js#87

Checklist

• PR description included
• yarn test passes

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

[david-mcafee]

Thanks for moving these! LGTM!