Auth:  Add support for forcing authentication in anonymous mode and modify SignIn to use it instead of redirect (#25567)

* Forbid additional redirect urls

* Optionally force login in anonymous mode

* Update LoginCtrl page to ignore redirect parameter

* Modify SignIn to set forceLogin query instead of redirect

* Pass appUrl to frontend and use URL API for updating url query

* Apply suggestions from code review

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

* Fix SignIn test

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>