✨ Add support for nested fields in log entries and JSON marshalling

This commit introduces the ability to handle nested fields within log entries.
The  file has been updated with a  function
that transforms flat keys with a : delimiter (e.g., obj:foo) into nested
JSON objects (e.g., ).

The  file includes new test cases to verify that:
- Nested fields are correctly unmarshalled from string representations.
- Nested fields are correctly marshalled into JSON objects.

This enhancement allows for more structured and organized metadata within log entries.

models/metas.go

@@ -2,6 +2,7 @@ package models
 
 import (
 	"encoding/json"
+	"strings"
 	"time"
 )
 
@@ -33,9 +34,32 @@ func (ms Metas) Map() map[string]any {
 			}
 		}
 	}
+
+	// Next we have to go through them again to find nested fields
+	parseNestedFields(out)
+
 	return out
 }
 
+func parseNestedFields(f map[string]any) {
+	for k, v := range f {
+		if strings.Contains(k, ":") {
+			idx := strings.Index(k, ":")
+			top := k[:idx]
+			bottom := k[(idx + 1):]
+
+			nest, ok := f[top].(map[string]any)
+			if !ok {
+				nest = map[string]any{}
+			}
+			nest[bottom] = v
+			parseNestedFields(nest)
+			f[top] = nest
+			delete(f, k)
+		}
+	}
+}
+
 // Implements json.Marshaler
 func (ms Metas) MarshalJSON() ([]byte, error) {
 	return json.Marshal(ms.Map())