Improve UI for global reset "remember my choice" cookies

[baszoetekouw]

Important

Original story of #345 with more/better user feedback. We decided not to implement this in the first version of OpenConext/OpenConext-engineblock#1956, because it would require Profile to have access to EngineBlock's "remember-my-choice" cookie, or implement a complex way to relay this information from EngineBlock to Profile.

In OpenConext/OpenConext-engineblock#1956 we describe a feature where a user can specify per SP which IdP they want to use. On a next login to that SP, the preferred IdP will be used automatically without user interaction.

This story will allow a user to reset that choice (globally, for all SPs at the same time).

The settings of which SP should use which IdP are stored in a cookie rememberedidps which is set on the main OpenCOnext domain (so if profile lives on https://profile.openconex.dev the cookie lives on the .openconext.dev domain).

The cookie is a base64-encoded deflated json structure like this:

{
  "https://sp_entityid_1": { "idp": "https://idp_entityid_1", "time": 1784534287 },
  "https://sp_entityid_2": { "idp": "https://idp_entityid_2", "time": 1784512345 }
}

In profile, the presence of this cookie should enable the following:

• On the "my personal data" screen, add an entry at the bottom that shows how many choices are remembered and an option to reset them:

  

  If the cookie is not present, is invalid (base base64, bad deflation data, bad json) or has empty json, show the text "No choices remembered" and hide the reset option.

• If the user presses the button, show a confirmation popup:

  

• If the user presses "Reset all", remove the cookie.

[baszoetekouw]

As discussed, we cannot show how many choices are remembered. So the profile screen should look like this:

The confirmation dialog can stay as designed above.

Depending of the result returned by Engineblock's reset endpoint (see OpenConext/OpenConext-engineblock#2085), show a info dialog with "Your saved login preferences were successfully removed" or "There were no saved login preferences to remove". Those can be simple dialogs.