Improve file upload security and error handling in ovos-support script

[coderabbitai]

Security improvements needed for the file upload functionality in ovos-support script:

1. Add user confirmation prompt before upload to allow inspection of potentially sensitive data
2. Add proper verification of upload success by checking HTTP status code
3. Add error handling for curl failures and network issues
4. Extract response body and status code separately for better error reporting

Related PR: #129
Related comment: #129 (comment)