[FEATURE] Network Panel: desktop notification on any error

Submission checklist

• I have searched existing issues and confirmed this has not been requested before.
• I have checked existing pull requests for similar changes.

Feature type

New functionality

Feature summary

All network errors reported by the network subsystem (NetworkManager) are silent.

This would be solved by throwing a desktop notification reporting any errors, or even connection changes.

Motivation / use case

Feedback on error or change is pretty much basic functionality for a network management user interface. It would probably solve issues #4362 and partially #4051.

Proposed solution

Errors from the subsystem are already logged, but not handled. So what would be needed is an error/event handler for this, at minimum sends a desktop notification with the error message.

Alternatively: a configurable hook (per error class / output message match?) that would/could be used to send a notification or perform another action.

Alternatives considered

No

References / related projects

No response

Additional context

No response