Why Producer not support send messages for batch

[sycoral]

Is your feature request related to a problem? Please describe.
4.x client support send batch，but 5.x not support，and the producer implement support batch

Describe the solution you'd like
Add function List send(List messages) throws ClientException;

[lizhanhui]

@sycoral Protocol Buffers are not designed to handle large messages. See https://protobuf.dev/programming-guides/techniques/#large-data

We should consider adding streaming publish API, instead.

[fanlunyong]

这是来自QQ邮箱的自动回复邮件。   您好，请您放心您的邮件我已经收到。我将在看过邮件后，尽快给您回复。