YARN-9889. [UI] Add Application Tag column to RM All Applications table. Contributed by Kinga Marton

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMAppsBlock.java

@@ -60,6 +60,7 @@ public class RMAppsBlock extends AppsBlock {
     TBODY<TABLE<Hamlet>> tbody =
         html.table("#apps").thead().tr().th(".id", "ID").th(".user", "User")
           .th(".name", "Name").th(".type", "Application Type")
+          .th(".apptag", "Application Tags")
           .th(".queue", "Queue").th(".priority", "Application Priority")
           .th(".starttime", "StartTime")
           .th("launchtime", "LaunchTime")
@@ -130,6 +131,10 @@ public class RMAppsBlock extends AppsBlock {
           StringEscapeUtils.escapeEcmaScript(StringEscapeUtils.escapeHtml4(app
             .getType())))
         .append("\",\"")
+        .append(
+          StringEscapeUtils.escapeEcmaScript(StringEscapeUtils.escapeHtml4(
+            app.getApplicationTags() == null ? "" : app.getApplicationTags())))
+        .append("\",\"")
         .append(
           StringEscapeUtils.escapeEcmaScript(StringEscapeUtils.escapeHtml4(app
              .getQueue()))).append("\",\"").append(String