Make the stdout log appender configurable

[MichaelScofield]

What type of enhancement is this?

Configuration

What does the enhancement do?

Logging to stdout makes the log rotation out of the control of GreptimeDB, which could make file system exploded especially in the situation that GreptimeDB is started by systemd and the journald is not properly configured. So I think it's better to make the stdout log appender configurable, users could remove the behavior of logging to stdout. Of course for the ease of use, logging to stdout is enable by default.

Implementation challenges

No response