Extend upload endpoint to accept all formats specified in openAPI

[joyceyuu]

That's the file views/project.py. Method project_clks_post needs to support both upload types. The plan is to give the new format the same treatment as the old one. That is:

• take the data as-is and save it in a file.
• call the handle_raw_upload task to deal with it. (a separate issue)

Additionally, we would also have to check that the uploaded data is what we expect. Either the json has a 'clks' element, or a 'clknblocks' one. That has to match the 'use_blocking' flag in the project info in the database.