Go: refactor system stats (#17089)

### Summary

Move stats to a specific service from system

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

internal/admin/router.go

@@ -244,6 +244,8 @@ func (r *Router) Setup(engine *gin.Engine) {
 			protected.POST("/license", r.handler.SetLicense)
 			protected.POST("/license/config", r.handler.UpdateLicenseConfig)
 			protected.GET("/license", r.handler.ShowLicense)
+
+			RegisterEERouter(protected, r)
 		}
 	}
 

internal/admin/router_ee.go

@@ -22,3 +22,6 @@ import (
 
 func SetupEERouter(engine *gin.Engine) {
 }
+
+func RegisterEERouter(protected *gin.RouterGroup, r *Router) {
+}