add viewer healthcheck path (#11019) - merge stable-24-3 (#11045)

Author: StekPerepolnen

ydb/core/viewer/viewer.cpp

@@ -1,5 +1,6 @@
 #include "viewer.h"
 #include "counters_hosts.h"
+#include "viewer_healthcheck.h"
 #include "json_handlers.h"
 #include "log.h"
 #include "viewer_request.h"
@@ -522,6 +523,10 @@ class TViewer : public TActorBootstrapped<TViewer>, public IViewer {
             ctx.ExecutorThread.RegisterActor(new TCountersHostsList(this, ev));
             return;
         }
+        if (path.StartsWith("/healthcheck")) { // healthcheck no auth scrapping
+            ctx.ExecutorThread.RegisterActor(new TJsonHealthCheck(this, ev));
+            return;
+        }
         // TODO: check path validity
         // TODO: cache
         if (msg->Request.GetPathInfo().StartsWith('/')) {