Testclusters logging improovements (#37354)

- Cluster logs are only indented as  node name is already in the logs
- silence logging on shutdown
- have fully qualified name as node and cluster name

Author: alpar-t

buildSrc/src/main/java/org/elasticsearch/gradle/testclusters/ElasticsearchNode.java

@@ -288,7 +288,7 @@ private void logFileContents(String description, Path from) {
         logger.error("{} `{}`", description, this);
         try(Stream<String> lines = Files.lines(from, StandardCharsets.UTF_8)) {
             lines
-                .map(line -> "  [" + name + "]" + line)
+                .map(line -> "  " + line)
                 .forEach(logger::error);
         } catch (IOException e) {
             throw new UncheckedIOException(e);

buildSrc/src/main/java/org/elasticsearch/gradle/testclusters/TestClustersPlugin.java

@@ -332,7 +332,9 @@ private static void shutdownExecutorService() {
     }
 
     private static void shutDownAllClusters() {
-        logger.info("Shutting down all test clusters", new RuntimeException());
+        if (logger.isDebugEnabled()) {
+            logger.debug("Shutting down all test clusters", new RuntimeException());
+        }
         synchronized (runningClusters) {
             runningClusters.forEach(each -> each.stop(true));
             runningClusters.clear();