updated StructureDB and FragDB using the new code

doc/tests/data/port_str_db.dat

doc/tests/scripts/loop_frag_db.py

doc/tests/scripts/loop_structure_db.py

doc/tests/test_doctests.py

extras/data_generation/frag_db/build_frag_db.py

extras/data_generation/structure_db/README

...data_generation/structure_db/assign_structure_profiles.py

extras/data_generation/structure_db/build_structure_db.py

...data_generation/structure_db/create_structure_profiles.py

extras/data_generation/structure_db/get_data_from_smtl.py

...ructure_db/prepare_slurm_submission_structure_profiles.py

...ion/structure_db/submit_structure_profile_calculations.py

loop/data/CMakeLists.txt

loop/data/portable_frag_db.dat

loop/data/portable_structure_db.dat

loop/src/structure_db.hh

modelling/tests/data/port_frag_db.dat

modelling/tests/data/port_str_db.dat

modelling/tests/test_loop_candidates.cc