Add endpoint to remove "remember my choice" cookie

In https://github.com/OpenConext/OpenConext-engineblock/issues/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 ticket describes an endpoint that allows users to reset these choices.

• Add a global configuration option wayf.reset_choice_per_idp_redirect to parameters.yml that contains a url to redirect the user to after resetting the choice (see below)

• Implement a front-end page/endpoint as follows:

  • It is located at https://engineblock.dev.openconext.org/reset-remember-wayf
  • When the user visits this page, check if they send a cookie rememberedidps and if so, remove it.
  • Log a message with level INFO and message "WAYF-remember-my-choice cookie removed (had <number> entries)"
  • After removing the cookie, redirect the user (302) to the url set in wayf.reset_choice_per_idp_redirect

Start with parameters.yml and trace the existing WAYF routing and endpoint handlers to locate the /reset-remember-wayf entry point. Check the relevant endpoint tests or add coverage for cookie removal, INFO logging, and the 302 redirect configured by wayf.reset_choice_per_idp_redirect; done means all specified behaviors are verified.