chore(repo): jest heap usage

[HuiSF]

Description of changes

• Broke down the Datastore.test suite into 3 suites to avoid jest heap out of memory
• Enabled --logHeapUsage for jest runs to monitor the heap sizes used running tests

For Datastore.test:

• Original heap size: ~3.7GB
• After broke down the test suite:
  • Datastore.test: ~880MB
  • DataStore.CustomPrimaryKey.test: ~1.4GB
  • DataStore.BasicOperations.test: ~1.3GB
  • DataStore.TypeDefinitions.test: ~620MB

Issue #, if available

Description of how you validated changes

Checklist

• PR description included
• yarn test passes
• Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)

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

[github-actions]

⚠️ This PR includes manual changes to the "aws-amplify" package.json file, which can have library-wide implications.

Please ensure that this PR:

• Does not modify "@aws-amplify/*" dependency versions, which may misalign core dependencies across the library.

A repository administrator is required to review & merge this change.

[github-actions]

⚠️ This PR includes manual changes to the "aws-amplify" package.json file, which can have library-wide implications.

Please ensure that this PR:

• Does not modify "@aws-amplify/*" dependency versions, which may misalign core dependencies across the library.

A repository administrator is required to review & merge this change.

[svidgen]

Look OK on spot check. And the bottom line adds up:

Tests:       14 skipped, 1116 passed, 1130 total

Thanks!