Fix application start duration log "Failed to load class org.slf4j.impl.StaticLoggerBinder." (#5678)

* Fix application start duration log "Failed to load class "org.slf4j.impl.StaticLoggerBinder"." when use kafka reporter. because kafka reporter use slf4j-api, but no implementor for slf4j.

* Polishing.

* Adapter slf4j Logger of agent used to skywalking agent Logger.

* Make the comments more accurate.
Co-authored-by: 吴晟 Wu Sheng <wu.sheng@foxmail.com>