build: make all shall include also BuildTranslations

This also adds a new devel-target 'binaries' that builds all
binaries needed for running gcompris (and excluding
BuildTranslations).

BUG: https://phabricator.kde.org/T4809
REVIEW: 129640
(cherry picked from commit 9d83e6c5badd3447625f3a6be27f65f5b7455102)