Need a better error message to be displayed

**Describe the bug**
When we sync files with cloud storage, if the files were moved from the source location, instead of showing that the files were not found, the error message suggests to check CORS policy. It would be better if the error was handled and the message displayed to the user suggests action based on error codes of the request. Concisely, have separate messages displayed for S3 response code 404 (not found) or 403 (access denied)

**To Reproduce**
Create a new project on LabelStudio enterprise. https://app.heartex.com/projects

Steps to reproduce the behavior:
1. Go to 'settings -> cloud storage'
2. Setup an S3 storage that has a few images in it and sync storage.
3. Move the files in S3 to a different location/prefix.
4. Click on a task
5. Note the error suggests to check CORS policy.

**Expected behavior**
If the resource is not found, please handle the error based on the response code to say file not found at location (404) and an access denied message for code 403 (likely but please check aws s3 documentation) to suggest changing the CORS policy.

**Screenshots**

**Environment (please complete the following information):**
- OS: N/A cloud version
- Label Studio Version [e.g. 0.8.0] - label Studio enterprise version

**Additional context**

In large organisations usually different teams have different levels of access to the infrastructure. It is a small change but it can impact development timelines when teams are sat at different time zones. I should appreciate how useful label-studio has been for us! Thanks, happy to provide more details if required.