Remove CSV_UPLOAD_MAX_SIZE config

[dpgaspar]

CSV_UPLOAD_MAX_SIZE only affects CSV uploads as the name implies, yet we have Excel and columnar upload also. Also this prevention should be made at the webserver level using max_body_size or similar.

there are some trade offs here: pros:

• Usually faster and more efficient as the web server can reject the request before it reaches the application code.
• Helps to prevent denial-of-service attacks by limiting resource consumption. cons:
• does not provide a nice server response