InFORM Single Sign On change to OKTA

As an Inform user, I would like to be able to use my Single Sign On credentials in Okta to easily authenticate into Inform.

Notes

After switching to Okta in production, we encountered two errors, both resolved by clearing one's cache. One was a 400 Bad Request error upon trying to login (this was also correctable by changing the Single Log Out URL), and one was hitting the InFORM link in @CFAhome after an Inform session timed out and being directed to the @CFAhome page again.

Acceptance Criteria

1. When a user clicks a link from @CFAhome to inform.cfahome.com, and the user is not currently authenticated in Inform (because they logged out or their session timed out) or Okta, the user should be redirected to Okta to authenticate. Once a user has been authenticated in Okta, the user should be authenticated in Inform without any additional user action required, and redirected to the MMS splash page
2. When a user clicks a link from @CFAhome to inform.cfahome.com, and the user is not currently authenticated in Inform (because they logged out or their session timed out), but they are authenticated with Okta, the user should be be authenticated in Inform without any additional user action required, and redirected to the MMS splash page
3. When a user clicks the Logout button in Inform, the user's session should be cleared and the user should be redirected to @CFAhome. The user should remain logged in to Okta and not require the user to re-enter their credentials
4. When a user's session times out in Inform, their session should be cleared and the user should be redirected to @CFAhome. The user should remain logged in to Okta and not require the user to re-enter their credentials
5. When a user goes directly to the inform.cfahome.com URL, and the user is not currently authenticated in Inform or Okta, the user should be redirected to Okta to authenticate. Once a user has been authenticated in Okta, the user should be authenticated in Inform without any additional user action required, and redirected to the MMS splash page
6. When a user goes directly to the inform.cfahome.com URL, and the user is not currently authenticated in Inform, but they are authenticated with Okta, the user should be be authenticated in Inform without any additional user action required, and redirected to the MMS splash page