This commit completes the implementation of nested field support.
- :
- now correctly handles and by recursively flattening them into format.
- Introduced for recursive map marshalling.
- Refactored for cleaner buffer writing.
- : Added comprehensive test cases for nested JSON, nested maps, double-nested maps, and nested keys within JSON to ensure correct marshalling and unmarshalling.
- : Updated tests to reflect the new nil handling and removed redundant JSON object test.
This allows for more flexible and structured data representation within log entries.
