[SPARK-51452][UI] Improve Thread dump table search

### What changes were proposed in this pull request?

This PR improves thread dump search by:
- query with pattern `tr[id^="thread_"]` w/o further patten matching
- short-circuit the searching loop if found
-
### Why are the changes needed?

code refactoring for perf & cost

### Does this PR introduce _any_ user-facing change?
no

### How was this patch tested?

![image](https://github.com/user-attachments/assets/306c6d72-8182-4a96-85a0-c3a19d733be7)

### Was this patch authored or co-authored using generative AI tooling?
no

Closes #50225 from yaooqinn/SPARK-51452.

Authored-by: Kent Yao <yao@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>

Author: yaooqinn

core/src/main/resources/org/apache/spark/ui/static/table.js

@@ -82,31 +82,26 @@ function onMouseOverAndOut(threadId) {
 }
 
 function onSearchStringChange() {
-  var searchString = $('#search').val().toLowerCase();
+  const searchString = $('#search').val().toLowerCase();
   //remove the stacktrace
   collapseAllThreadStackTrace(false);
-  if (searchString.length == 0) {
-    $('tr').each(function() {
+  $('tr[id^="thread_"]').each(function() {
+    if (searchString.length === 0) {
       $(this).removeClass('d-none')
-    })
-  } else {
-    $('tr').each(function(){
-      if($(this).attr('id') && $(this).attr('id').match(/thread_[0-9]+_tr/) ) {
-        var children = $(this).children();
-        var found = false;
-        for (var i = 0; i < children.length; i++) {
-          if (children.eq(i).text().toLowerCase().indexOf(searchString) >= 0) {
-            found = true;
-          }
-        }
-        if (found) {
-          $(this).removeClass('d-none')
+    } else {
+      let found = false;
+      const children = $(this).children();
+      let i = 0;
+      while(!found && i < children.length) {
+        if (children.eq(i).text().toLowerCase().indexOf(searchString) >= 0) {
+          found = true;
         } else {
-          $(this).addClass('d-none')
+          i++;
         }
       }
-    });
-  }
+      $(this).toggleClass('d-none', !found);
+    }
+  });
 }
 /* eslint-enable no-unused-vars */