feat: Auth and User System

[danorlando]

feat: Auth and User System

Api:

• Implements OAuth2 JWT local authentication system
• Adds user and token schemas
• Routes use JWT verification middleware for authorizing request, then passes request to auth.controller
• auth controller handles request/response and error handling, and uses auth.service for communicating with data layer
• auth service handles CRUD operations via user model
• OAuth is done via node Passport, which includes local, jwt, google, and facebook strategies
• Includes support for Google oauth
• Includes password reset functionality: when reset request is sent, displays a link with one-time reset token
• automatic logout when access token expires
• modifies the conversation and preset model binding to user through user id instead of username
• when first user is registered, any previously created conversations and presets will be migrated to that account.

Client:

• App.jsx refactored to remove api calls - moved to Root
• auth and user-related logic is contained in AuthContext
• when user logs in, access token is set on the Axios authorization header config (the api's get the access token from the authorization header). A secure token cookie is also set to keep the user logged in if they close the browser window or refresh, where the AuthContext then uses the cookie to get the token and re-populate the auth/user state.
• Includes login and registration forms with comprehensive validation
• requires a .env file to be placed in client folder. A /client/.env.example file has been included with instructions

Notes:

• apis are included for token refresh / access token exchange, but this feature is not fully implemented as token exchange significantly increases the complexity on the client side, and is perhaps beyond the necessities of this application. I will either complete the implementation on the client when I have time or remove.
• api also includes the code for handling emails for forgot password and email verification. this is still a work in progress and is not yet functional.
• facebook oauth strategy is also included, but I've purposely left it out of the readme and should be left out of release notes for now because I honestly had such issues with registering the app with facebook that it made me just want to rip it all out. If i don't end up completing the facebook implementation, I will just remove that code in the next pr.