aider: Update NewExtendedEvent to accept base event as an argument and populate additional fields.

# Aider chat conversation:

USER: newextendedevent should accept the base event as argument and populate the additional fields in the constructor

ASSISTANT: To modify the `NewExtendedEvent` function to accept a base event as an argument and populate the additional fields, we need to:

1. Update the `NewExtendedEvent` function in `simplelog.go`.

Here is the *SEARCH/REPLACE* block:

simplelog.go
```go
<<<<<<< SEARCH
func NewExtendedEvent(level, message string, data json.RawMessage, file string, line int) ExtendedEvent {
	return extendedEvent{
		Event: NewEvent(level, message, data),
		File:  file,
		Line:  line,
	}
}
=======
func NewExtendedEvent(baseEvent Event, file string, line int) ExtendedEvent {
	return extendedEvent{
		Event: baseEvent,
		File:  file,
		Line:  line,
	}
}
>>>>>>> REPLACE
```

simplelog.go

@@ -125,9 +125,9 @@ func (e extendedEvent) GetLine() int {
 	return e.Line
 }
 
-func NewExtendedEvent(level, message string, data json.RawMessage, file string, line int) ExtendedEvent {
+func NewExtendedEvent(baseEvent Event, file string, line int) ExtendedEvent {
 	return extendedEvent{
-		Event: NewEvent(level, message, data),
+		Event: baseEvent,
 		File:  file,
 		Line:  line,
 	}