feat: tpa automatic logout with a single redirect

[Cup0fCoffee]

Description

Current Third Party Authentication logout requires a redirect from the SSO IDP to the LMS to handle IDAs logout, i.e. we need to visit the <LMS>/logout twice. This PR attempts to handle the TPA logout with only one visit to <LMS>/logout.

Testing instructions

1. Add TPA_AUTOMATIC_LOGOUT_ENABLED = True to edx-platform/lms/envs/devstack.py
2. Replace self.tpa_logout_url = tpa_pipeline.get_idp_logout_url_from_running_pipeline(request) in edx-platform/openedx/core/djangoapps/user_authn/views/logout.py with self.tpa_logout_url = "https://example.com/logout" (to simplify testing)
3. Launch LMS and Studio e.g. make dev.up.lms+cms
4. Check the network tab and ensure that the user is logged out from both the LMS and Studio before being redirected to https://example.com/logout (fake IDP logout URL)

Supporting information

Private ref BB-8759

Deadline

"None" if there's no rush, or provide a specific date or event (and reason) if there is one.

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[Cup0fCoffee]

@sarina pinging you here re this comment. The new PR is up to date and passing all the tests.

[sarina]

Hi @Cup0fCoffee I was only commenting on the previous PR because it was one of our top 10 oldest. I don't have any context here and as I mentioned in the previous PR, I don't know who does. Do you think you can find a reviewer?

[Cup0fCoffee]

@sarina Ok, I'll see if we can get a Core Contributor for our team assigned to this.

[Agrendalath]

@Cup0fCoffee, I'm trying to test this in the local Tutor environment, but I am not getting redirected anywhere from the logout page (http://local.openedx.io:8000/logout). Instead, I'm seeing the following error in the console:

Uncaught TypeError: this.unbind is not a function
    jQuery 13
    <anonymous> http://local.openedx.io:8000/static/js/logout.js:19
    jQuery 8

It comes from this line. I tried running tutor dev exec lms npm run build-dev, but it did not fix the issue. I'm getting a correct redirect on the master branch.

[Cup0fCoffee]

@Agrendalath Yep, I'm getting the same error. However, I was able to figure it out. This issue is not caused by the changes (master fails for me the same as the branch from this PR, if you keep the self.tpa_logout_url = "https://example.com/logout"), but due to the logic of the logout script and the local setup. Basically, to make it work locally, you need to remove the services that are not setup on local environment by commenting out the items in the IDA_LOGOUT_URI_LIST located in lms/envs/devstack.py.

[Agrendalath]

👍

• I tested this: checked that the user is correctly redirected to the logout_url from Other/Advanced TPA settings
• I read through the code
• I checked for accessibility issues: n/a
• Includes documentation: n/a

[edx-pipeline-bot]

2U Release Notice: This PR has been deployed to the edX staging environment in preparation for a release to production.

[edx-pipeline-bot]

2U Release Notice: This PR has been deployed to the edX production environment.