fix(update): return better errors

[lucarin91]

Motivation

We should improve the errors returned during the update operation, allowing the caller to be able to understand what happened and if to retry

Change description

1. Add a code field in the error structure, both in normal HTTP calls and in SSE ones, with a set of easy-to-match strings
2. Return the full underline error in the SEE error event and in the command line
3. code refactoring (hopping it is more redable)

The error codes for now are:

• NO_INTERNET_CONNECTION
• OPERATION_IN_PROGRESS
• UNKNOWN_ERROR

Both NO_INTERNET_CONNECTION and OPERATION_IN_PROGRESS could be considered retryable errors.

Additional Notes

Reviewer checklist

• PR addresses a single concern.
• PR title and description are properly filled.
• Changes will be merged in main.
• Changes are covered by tests.
• Logging is meaningful in case of troubleshooting.