Make ELPA (again) compile and run correctly with MPI and 32bit ints

.gitlab-ci.yml

ci_test_scripts/.ci-env-vars

ci_test_scripts/generate_gitlab_ci_tests.py

ci_test_scripts/run_ci_tests.sh

ci_test_scripts/run_distcheck_tests.sh

ci_test_scripts/run_project_tests.sh

src/elpa2/elpa2_bandred_template.F90

src/elpa2/elpa2_trans_ev_band_to_full_template.F90

src/elpa_generalized/cannon_back_template.c

src/elpa_impl_generalized_transform_template.F90

src/helpers/fortran_blas_interfaces.F90

src/helpers/fortran_scalapack_interfaces.F90

src/helpers/scalapack_interfaces.h

...driver/legacy_interface/legacy_complex_driver_c_version.c

.../C/driver/legacy_interface/legacy_real_driver_c_version.c

...legacy_interface/legacy_single_complex_driver_c_version.c

...er/legacy_interface/legacy_single_real_driver_c_version.c

.../elpa1/legacy_interface/legacy_complex_1stage_c_version.c

test/C/elpa1/legacy_interface/legacy_real_1stage_c_version.c

.../elpa2/legacy_interface/legacy_complex_2stage_c_version.c