[PROJECT HEALTH] Component Unit Testing

### User Story

As a developer, I want to ensure my React Components work in isolation, assuming all other components do not work.

### Technical Tasks

- Create automated unit tests with Selenium or a similar UI testing library to test individual components for proper functionality and edge cases
- Unit tests should be REALISTIC: they reflect typical user behavior and interaction
- Ensure proper documentation on how future unit tests should be written

Learning Resources:
- https://tuskr.app/learn/unit-testing
- https://www.selenium.dev/documentation/overview/
- https://www.browserstack.com/guide/automation-using-selenium-javascript
- https://jestjs.io

### Acceptance Criteria

- Each component has some unit tests (up to assignee as to how many) related to its functionality
- Documentation (either in code or wiki) outlines current and future practices for unit testing.

### Related Issues

- #137