Correct Third-Party Code Copyright and NOTICE File #549

Describe the bug, including details regarding any error messages, version, and platform.

Currently, we have incorrect handling of third-party code copyright and NOTICE information, which violates the requirements of the Apache License 2.0 (AL2):

Incorrect LICENSE Headers

• The referenced third-party code, such as portions from Netty, does not retain the original LICENSE headers.
• This leads to a lack of proper attribution, as the copyright for these code portions remains with the original authors.

Incomplete NOTICE File

• The project's NOTICE file does not include the required NOTICE information from third-party libraries like Netty.
• Libraries like Guava, which do not provide a NOTICE file, are currently irrelevant to this issue.