introduce log level setting

[webern]

When troubleshooting Bottlerocket, we might want to increase logging verbosity. Many of our programs have a --log-level argument with the values error, warn, info, debug, trace. All of our programs default to info.

Should we introduce the ability to change this log-level through the settings API? If so, should we try to make it an instantaneous change, or should it be something that requires a reboot?

Note: this is probably distinct from #1931 which is kubelet-specific.