Make the CSDS indepedent from SWIFT's module

.clang-format

doc/source/NewScheme/index.rst

examples/create_snapshot.py

examples/reader_example.py

format.sh

src/Makefile.am

src/chemistry/GEAR/csds_chemistry.h

src/chemistry/none/csds_chemistry.c

src/chemistry/none/csds_chemistry.h

src/csds_chemistry.h

src/csds_cosmology.c

src/csds_cosmology.h

src/csds_fields.c

src/csds_fields.h

src/csds_gravity.h

src/csds_header.c

src/csds_header.h

src/csds_hydro.h

src/csds_index.c

src/csds_index.h