Automagically connect Thundermail Calendar in FTUE

[davinotdavid]

Description of the Change

• Updated docker-compose.yml container ports not to clash with thunderbird-accounts when running locally
• Added TB_ACCOUNTS_CALDAV_URL env var.
• Added POST '/caldav/oidc/auth' route to attempt to connect to the CalDAV through the OIDC token.
• Removed the ConnectYourCalendarThundermailStep as we don't need it anymore + related i18n and enum entries.

Here's the flow:

• Frontend makes a POST request to /caldav/oidc/auth
• Appointment's Backend makes a POST request to Account's Backend /appointment/caldav/setup/ passing the APPOINTMENT_CALDAV_SECRET and the current logged in user's OIDC token
• Account's Backend deletes previously existing App Passwords that match a specific label and creates a new App Password in Stalwart. The password is returned in plain text as we will need it in Appointment's backend to connect to it but it is hashed when saved
• Appointment's Backend takes the subscriber's email + newly created App Password and connects to the CalDAV server + creates the ExternalConnection entry

Warning

Requires thunderbird/thunderbird-accounts#616 to be merged in first for the best experience on testing this

How to test it

Alright, first of all, this is a joint effort with the thunderbird-accounts repo so make sure you are in the branch appointment-auto-setup-caldav (thunderbird/thunderbird-accounts#469) and you are able to run a docker compose up in both thunderbird-accounts and this branch in Appointment.

Make sure you have the .env var APPOINTMENT_CALDAV_SECRET set in both thunderbird-accounts and this branch to the same values.

Accounts Prerequisites

• Navigate to the Django Admin in http://localhost:8087/admin and login with user admin@example.org and password admin.
• Create a Subscription Plan manually in http://localhost:8087/admin/subscription/plan/add/. None of the information here actually matter except for the Product which has to be an active product.
• Now navigate again to http://localhost:8087/ and you should be redirected to the /subscribe page.
• Use Paddle's test cards for the checkout.
• After you are redirected to the dashboard, you are all set!

PS: This whole step is required because only then we will have the authenticate.User model created + the actual Stalwart account to create the App Password.

Steps to test, now in Appointment-land

• Navigate to http://localhost:8090, if you are redirected to Keycloak, login with the same admin@example.org / admin as before.
• Go through the FTUE until the step to select which calendar to connect with and select Thundermail Calendar
• Click Next and see that you are now in the Booking Page step with the Stalwart Calendar pre-selected. All that without manually creating an App Password!

Benefits

• 1 click configuration for Thundermail Calendar!

Applicable Issues

Fixes #1352