Provide further guidance for import failures
The MR expands GPT Data Generator troubleshooting doc with more guidance for import failures:
- added exception handler for
/projects/importPOST request - what to do if import is stuck
- guide users on how to troubleshoot import failures
- revamped troubleshooting for Large Project import failures
Error output example:
Closes #399 (closed)
Edited by Nailia Iskhakova