Add a generic view to download csv from list of dicts

[reskyner]

Because smiles strings have to be url encoded on the front-end, it is better to pass them to the back-end to produce a csv file that can be downloaded (so the smiles strings can be url decoded, added to a csv, and then passed back as a download). This is also an advantage as the function can be used to write any csv file from any list of dicts in the future.

Proposed solution here: https://stackoverflow.com/questions/60150927/csv-from-list-of-dictionaries-with-differing-length-and-keys

[reskyner]

from urllib.parse import unquote
url = unquote(url)

or

from urllib import unquote

url = unquote(url).decode('utf8')