Issue Summary

When testing connection for an OAuth 2.0 integration fails, no error details are displayed in application logs.

Steps to Reproduce

1. Add an invalid OAuth 2.0 configuration
2. On the list of configurations, click 'Test connection'
3. Await error: 'The connection has failed. Check the application logs for details.'

Expected Results

Application logs contain details about the error.

Actual Results

Application logs have no additional information about the error.

Workaround

The error details are sent back from the server in REST response. Use browser's dev tools to preview network communication, and the error can be extracted from response body:

{
  "success": false,
  "error": "<details>"
}