Add endpoint to proxy local files inside datasets' data
for instance for:

<img width="2012" alt="Screenshot 2021-09-16 at 09 59 38" src="https://user-images.githubusercontent.com/326577/133573786-ca9b8b60-2271-4256-b1e4-aa05302fd2f3.png">

Add endpoint to proxy local files inside datasets' data: for instance for:

<img width="2012" alt="Screenshot 2021-09-16 at 09 59 38" src="https://user-images.githubusercontent.com/326577/133573786-ca9b8b60-2271-4256-b1e4-aa05302fd2f3.png">
