Issue #2954825 by rakesh.gectcr, tresti88, gnuget, borisson_, DamienGR,...

Issue #2954825 by rakesh.gectcr, tresti88, gnuget, borisson_, DamienGR, Prashant.c, amietpatial, alexpott, joachim, Berdir: Update the user.api.php documentation and add the correct type hints in the user's hooks implementations

(cherry picked from commit 400413fa)