feat(jellyfinapi): switch to API tokens instead of auth tokens

[gauthier-th]

Description

This PR changes the way Jellyseerr interacts with Jellyfin. Instead of using auth tokens from an admin user to connect to Jellyfin and perform all its requests, Jellyseerr will now use API tokens.

The API token will be automatically created from the previous auth tokens to ensure a smooth migration.

Screenshot (if UI-related)

To-Dos

• [x] Successful build pnpm build
• [ ] Translation keys pnpm i18n:extract
• [ ] Database migration (if required)

Issues Fixed or Closed

• Fixes #XXXX