almost done: using human readable controlled vocabulary for upload; TBD: using human readable controlled vocabulary for download, adapting 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: code completely messed up, but nested upload working; nevertheless download is NOT returning the nested view

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