Klever

Implemented in branch "feature_8515". I didn't remove support of old format of reports uploading. Now if you want to upload batch of reports, upload it to the same url (/reports/upload/) but instead of {'report': <dictionary>} send {'reports': <list of reports (dictionaries)>}.

This issue was implemented together with issues for Klever 1.0.

I merged the branch to master in 4339da97 as a part of branch core-new-formats. Unfortunately there isn't any users of a new request, so it wasn't tested in real environment. Let's see on #8514 in Klever 2.0.