Update script sequence to unzip first-level ZIP files

[larsvilhuber]

The scripts download openICPSR and Zenodo (Dataverse pending). If those contain ONLY or primarily ZIP files, i.e., at the root directory level, those ZIP files should be unzipped. The template report should be updated with a warning (for AEA) that the deposit has a ZIP file (which is not compliant with AEA policy, unless on Zenodo). The various repository-parsing scripts should then work automatically.

This script needs to be right after the download script.

[larsvilhuber]

See #58 and #59 for earlier attempts.

[larsvilhuber]

I believe this is actually working.