additional netcdf4 version install removed for setup_venv_hdfml.sh and reactivated ml Jupyter/... for mlt_modules_juwels.sh

reduced requirements_JUWELS_additionals to only not available (after mlt_modules_juwels are loaded), removed duplicated 'pip install -r' and uncommented matplotlib==3.2.0 and pandas==1.0.1 installations

changes in module versions to be compatible with HPC system (maybe diff pip version causes errors?) - put tensorflow at first

packages in *_additionals updated to new TensorFlow 2.5.0 environment and post_processing evaluate_generator(...) changed to evaluate(...)

changed to tensorflow==2.3.1 in requirements.txt and deleted requirements_tf2.txt and requirements_gpu.txt, because they are not needed anymore. Also updated mlt_modules_hdfml.sh

model.evaluate_generator changed, because it is deprecated and works with model.evaluate(generator, ...), updated mlt_modules_juwels.sh to Stages/2020 modules with Python/3.8.5

updated all run scripts with new Workflow class, HPC_setup script is calling now the new run_HPC.py script