almost done: using human readable controlled vocabulary for upload; TBD: using human readable controlled vocabulary for download, adapting pytests

#7: default values for stationmeta_global were defined; #4: nested upload tested for 'stationmeta_global' (not defining all metadata -- getting the rest from default values)

#4: nested upload for stations done; TBD: more testing (esp. pytest), use controlled vocabulary (related to #3)

#8: common base and test base is in place (but teardown of test_base has to be worked on for chained pytests)

#4: defined association tables also in models; now using one base for the whole app 'toardb'; this has now also to be adapted to test_base

#4: nested upload/download for roles (timeseries) working in production and pytest (uploading codes not human readable version)

#4: a typo made my days and nights long; after git crash do another upload; now detangling models_core and models_role again (different source code files)

#4: code completely messed up, but nested upload working; nevertheless download is NOT returning the nested view

#2: many-to-many relationship for role codes seem to work now within FastAPI; will probably again not work with pytest; has to be cleaned up again: just storing before crash

#1: pytest for uploading data with no_autoflush now working; added timeshift_from_utc to data insertion; added error message if trying to insert duplicates

#1: pytest for data established; renamed date_time to datetime; needed 'no_autoflush' in timeseries queries

adapted sphinx documentation to new structure (ONE app); some pretty printing (fastAPI does not provide sphinx extensions like django)

created ONE toardb app, also adapted pytests for toardb app (still very last test will throw an error for teardown; inserted example for url percent encoding