feat(eslint-config-react-app): Add jest & testing-library rules

Created by: MichaelDeBoey

Closes #8446 (closed) Closes #8959 (closed)

Since we now have ESLint 7 support, we need to wait until eslint-plugin-jest-dom & eslint-plugin-testing-library are ESLint 7 compatible.

• eslint-plugin-jest
  • PR
  • Released
• eslint-plugin-testing-library
  • PR
  • Released