Fix Focus Issues (v10.1.0)

[JRJurman]

Summary

This PR fixes the focus issues that have existed in Tram-One since major refactoring that removed the diffing library.

Changes

• Keep track of which elements get focus, and re-attach focus when that element would be re-rendered.
• added a parcel application for visually inspecting the app used for testing
• started using userEvent for events in the unit tests
• update jsdom version to v16

Checklist

• [x] PR Summary
• [x] Tests
• [x] Version Bump