feat: remove InsertBatch in gRPC message

[fengys1996]

I hereby agree to the terms of the GreptimeDB CLA

What's changed and what's your intention?

This pr mainly remove InsertBatch in gRPC message.

Checklist

• [x] I have written the necessary rustdoc comments.
• [x] I have added the necessary unit tests and integration tests.

Refer to a related PR or issue link (optional)

#544