Add testing library for `react-magic-motion` package

[Etesam913]

✨ Overview

• There needs to be testing for the <MagicMotion /> , <MagicExclude /> and <MagicTabSelect /> components
• The tests should run in CI using GitHub actions
• Make sure the test files are excluded from the package build

Some things to test

• <MagicMotion> returns a simple div with text
  • It should convert the div to a motion.div and have layout="true"
• <MagicMotion> returns a custom component imported from another file
  • The custom component should return a simple div with text
• <MagicMotion> returns a custom component imported from another file
  • The custom component should return another custom component
  • This other custom component should return a div with text
• <MagicMotion> should cause no error if it returns a nested <MagicMotion>
• <MagicMotion> should cause no error if it returns a nested <MagicExit>