refactor(server): auth (#5895)

Remove `next-auth` and implement our own Authorization/Authentication system from scratch.

## Server

- [x] tokens
  - [x] function
  - [x] encryption

- [x] AuthController
  - [x] /api/auth/sign-in
  - [x] /api/auth/sign-out
  - [x] /api/auth/session
  - [x] /api/auth/session (WE SUPPORT MULTI-ACCOUNT!)

- [x] OAuthPlugin
  - [x] OAuthController
  - [x] /oauth/login
  - [x] /oauth/callback
  - [x] Providers
    - [x] Google
    - [x] GitHub

## Client

- [x] useSession
- [x] cloudSignIn
- [x] cloudSignOut

## NOTE:

Tests will be adding in the future

packages/backend/server/src/global.d.ts

@@ -1,6 +1,6 @@
 declare namespace Express {
   interface Request {
-    user?: import('@prisma/client').User | null;
+    user?: import('./core/auth/current-user').CurrentUser;
   }
 }