E2E JWT Auth (Register, Login, Logout) + Toast Context + Responsive Signup Styling

[kennyjhcheng]

A lot of shit in this PR:

• I changed our Router configuration to be better practice
  • Landing page is /, pages with no Nav bar don't need a parent element
  • All other pages requiring login are children of /app route
• Added a ToastContextProvider, by using const openToast = useContext(ToastContext), you can pop open a Snackbar
• Some refactoring on NavBar for redirect and logout behavior
• Fixed styling for AdditionalProfileForm + BasicProfileForm that were broken, restyled SignupStats as part of that to be more responsive
• Created two form wrappers PaperForm and Form, for whether you want the Paper look
• JWT Authentication
  • You MUST setup mongoDB after this PR is merged
  • Users are automatically redirected to /login if not logged in
  • Auth.js and AuthService.js contain reducers, thunks, and services that integrate with backend
  • Signing up will create a user (only the first step of signup page)
  • you can log out
  • BE is also integrated with MongoDB, associated changes to controller and middleware too.

https://github.com/d-x-s/airon-fitness/assets/67628346/60a5e1c8-be7a-4abf-a50e-f2f9e88daeaf