style: add prettier import order

[dpilch]

Description of changes

Add a prettier plugin to sort imports. The plugin sorts import by package name as well as the import names in a given package.

CDK / CloudFormation Parameters Changed

N/A

Issue #, if available

N/A

Description of how you validated changes

• Unit tests
• E2E tests

Checklist

• [x] PR description included
• [x] yarn test passes

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