158 Co-located unit tests

[mwarman]

📢 Instructions

• Begin with a DRAFT pull request.
• Follow italicized instructions to add detail to assist the reviewers.
• After completing all checklist items, change the pull request to READY.

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🔧 Change Summary

Describe the changes included in this pull request. Link to the associated GitHub issue(s).

• fixes Co-located unit tests #158
• Moved unit tests from /__tests__ directories to be co-located with their respective source members.

📝 Checklist

Pull request authors must complete the following tasks before marking the PR as ready to review.

• Complete a self-review of changes
• Unit tests have been created or updated
• The code is free of [new] lint errors and warnings
• Update storybook stories as needed
• Update project documentation as needed, README, JSDoc, etc.

🧪 Steps to Test

Describe the process to test the changes in this pull request.

1. All unit tests should complete successfully.
2. All source code checks should be successful.

🔗 Additional Information

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