Introduced tracker plot (still on refac), moved get default to base class, added track parameter to datastore's get and set

docs for postprocessing, data handling methods/classes can now be imported from data_handling instead of subspaces

# Conflicts:
#	src/model_modules/flatten.py

# Conflicts:
#	src/helpers.py
#	src/model_modules/inception_model.py
#	src/plotting/postprocessing_plotting.py

Felix issue114 customise flatten tail

See merge request toar/machinelearningtools!96

moved helpers into new location, this is a commit only on the already finished doc strings, tests fail potentially fail with this part-wise commit

Added all docstrings, add example for hourly auth into join_settings. Will become untracked after next commit again.

moved helpers into new location, this is a commit only on the already finished doc strings, tests fail potentially fail with this part-wise commit