Add login page and login handling to frontend

[fisher60]

Summary

We need to replicate the functionality of the existing login from the Jinja/FastApi site to the Nuxt site.
The start of the existing logic can be observed in the source code and deployed to production

The styling/theme should utilize abandon tech colors (the ones already defined in the Nuxt site and on display on the demo site)

We can be flexible with the overall layout and styling of any components and do not need to replicate the original UI from AbandonAuth (the Jinja UI was rushed and not well thought out).

This feature must also handle session/login logic as well as logout logic. User authentication does not need to be persistently stored to maintain a long-lived session, but a user should be able to login and browse the site with their login, if their login has expired or is otherwise invalid, they should be logged out and redirected to the login page. This feature must implement the requests to log a user in with AbandonAuth and the overall logic for maintaining a login session (likely a router middleware)

Acceptance Criteria

1. A login page exists on the Nuxt site that contains one button for logging in with discord and successfully leads the user through the auth flow with discord, AbandonAuth, and results in the user being logged in with an AbandonAuth token (mimicking the login functionality of the existing Jinja/Fastapi frontend).
2. A handler exists to manage a session, logout users and redirect them back to the login page when their token expires, direct users with no auth to the login page (if a user tries to do something like navigate to /developer-applications and they are not logged in, they should be redirected to the login page.)