refactor: Add types

[Semro]

• extension scripts:
  • background
  • content
  • options
  • popup
  • players
    • loadNetflix
    • netflix
• server
• revisit test's scripts:
  • fixtures
  • main.spec.ts
• create a package to share types between server and client
• update server ci
• type chrome.runtime.sendMessage like socket.io events