Sven cummulative plot

See merge request !10

solves #39. 30 duplicate concat addresse in address_df caused an inflation of studies. Fixing that with drop_duplicates

classification completed. Additional contact and enrollment data in pop-up. Fixed typo for traditional chinese medicine

Sven classification of trials map

See merge request !9

Merge branch 'sven_classification_of_trials_map' of ssh://gitlab.gistools.geog.uni-heidelberg.de:2022/giscience/disaster-tools/covid-19-research-map into sven_classification_of_trials_map