Lift error finding utility to exceptions helpers

We have code used in the networking layer to search for errors buried in
other exceptions. This code will be useful in other locations so with
this commit we move it to our exceptions helpers.

Relates #28691

Author: jasontedor

core/src/main/java/org/elasticsearch/ExceptionsHelper.java

@@ -33,13 +33,15 @@
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Optional;
 import java.util.Queue;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 public final class ExceptionsHelper {
 
@@ -126,6 +128,10 @@ public static String stackTrace(Throwable e) {
         return stackTraceStringWriter.toString();
     }
 
+    public static String formatStackTrace(final StackTraceElement[] stackTrace) {
+        return Arrays.stream(stackTrace).skip(1).map(e -> "\tat " + e).collect(Collectors.joining("\n"));
+    }
+
     static final int MAX_ITERATIONS = 1024;
 
     /**

modules/transport-netty4/src/main/java/org/elasticsearch/transport/netty4/Netty4Utils.java

@@ -181,8 +181,7 @@ public static void maybeDie(final Throwable cause) {
              */
             try {
                 // try to log the current stack trace
-                final StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
-                final String formatted = Arrays.stream(stackTrace).skip(1).map(e -> "\tat " + e).collect(Collectors.joining("\n"));
+                final String formatted = ExceptionsHelper.formatStackTrace(Thread.currentThread().getStackTrace());
                 logger.error("fatal error on the network layer\n{}", formatted);
             } finally {
                 new Thread(