Add validation error is string handling

[kzscisoft]

Fix Server Validation Error String Handling

Issue: N/A

Python Version(s) Tested: 3.13

Operating System(s): Ubuntu 24.10

📝 Summary

Addresses case whereby the server sends a validation error which is a string, not a dict.

🔍 Diagnosis

IndexError when printing the validation error using the "prettify" methods.

🔄 Changes

Added logic for handling if the validation error is a string not a dict.

✔️ Checklist

• Unit and integration tests passing.
• Pre-commit hooks passing.
• Quality checks passing.