mod_admin: Do foldr over the blocks instead of foldl

This allows higher-priority modules to override or disable blocks that
lower-priority modules have defined, instead of the other way around.
(cherry picked from commit 9a654446329e3dd205743ad02827d31bdd2c2dc0)
mod_survey: Translation tweaks
(cherry picked from commit d5d61ac8cd0e71917bc3318a23f341844f3090bd)