[#14] Add tooling for unit, integration, and accessibility tests

[braxex]

Summary

• Configures tooling for all testing types (unit, integration, accessibility)
• Adds utilities for all testing types
• Adds baseline tests for all testing types

Addresses #14

Type of change

• [x] New feature (non-breaking change which adds functionality)
• [x] This is a documentation update

How To Test

1. Pull changes
2. Run yarn
3. Run unit tests (yarn test:cov) and verify that all unit tests pass
4. Spin up locally
5. Run integration tests (yarn test:cy:open) and verify that all integration tests pass

Checklist:

• [x] My code follows the style guidelines of this project and has no linting errors
• [x] I have performed a self-review of my code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation, including any applicable ADRs
• [x] My changes generate no new warnings
• [x] I have added tests that fail without these changes
• [x] New and existing tests (unit, integration, accessibility) pass locally
• [x] Documentation updated
• ~If there are security concerns they are addressed or ticketed after being discussed~