Introduced data directory for source and added download-all.sh script
This MR introduces a script execute the provided download.sh of each data source. It also makes sure there is a consistent data directory where all of the download.sh store their downloaded data.
This is a preparation step for the deployment of the downloaded sources: https://git.gfz-potsdam.de/dynamicexposure/collaboration/-/issues/409
Edited by Felix Delattre