Add CI scripts.

.ci/bb/breeze-mpim/test.all.clang

.ci/bb/breeze-mpim/test.all.nag

.ci/bb/breeze-mpim/test.all.nv

.ci/bb/breeze-mpim/test.ru-py.gcc

.ci/bb/breeze-mpim/utils.sh

.ci/bb/daint-cscs/test.all.cray

.ci/bb/daint-cscs/test.all.pgi

.ci/bb/daint-cscs/utils.sh

.ci/bb/levante-dkrz/install_prerequisites.sh

.ci/bb/levante-dkrz/test.all.gcc

.ci/bb/levante-dkrz/test.all.intel-classic

.ci/bb/levante-dkrz/test.icon-pio.intel-classic

.ci/bb/levante-dkrz/test.icon.gcc

.ci/bb/levante-dkrz/utils.sh

.ci/bb/run_all.sh