For the GET and PUT requests this handler returns the following JSON:
{
"init-log-level": <log level on service start>,
"current-log-level": <current log level>
}
Particular logger name could be specified by an optional logger query argument. Default logger is used, if no logger was provided.
PUT request changes the logger level to the value specified in the level query argument. Set it to the reset value, to reset the logger level to the initial values.