Refactor "dump" sub-command (#30240) (#30260)

Backport #30240 by wxiaoguang

Major changes:

* Move some functions like "addReader" / "isSubDir" /
"addRecursiveExclude" to a separate package, and add tests
* Clarify the filename&dump type logic and add tests
* Clarify the logger behavior and remove FIXME comments

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/setting/log.go

@@ -185,8 +185,13 @@ func InitLoggersForTest() {
 	initAllLoggers()
 }
 
+var initLoggerDisabled bool
+
 // initAllLoggers creates all the log services
 func initAllLoggers() {
+	if initLoggerDisabled {
+		return
+	}
 	initManagedLoggers(log.GetManager(), CfgProvider)
 
 	golog.SetFlags(0)
@@ -194,6 +199,10 @@ func initAllLoggers() {
 	golog.SetOutput(log.LoggerToWriter(log.GetLogger(log.DEFAULT).Info))
 }
 
+func DisableLoggerInit() {
+	initLoggerDisabled = true
+}
+
 func initManagedLoggers(manager *log.LoggerManager, cfg ConfigProvider) {
 	loadLogGlobalFrom(cfg)
 	prepareLoggerConfig(cfg)