Add support for backfillips

app/templates/nodes.html

@@ -1,7 +1,16 @@
 {% extends "base.html" %}
 
 {% block content %}
-<h3>nodes</h3>
+<div class="row data justify-content-between">
+    <div class="col col-4">
+        <h3>nodes</h3>
+    </div>
+    <div class="col col-2">
+        <span data-toggle="tooltip" data-placement="right" title="Recheck all IP addresses of all nodes">
+        <button type="button" class="btn btn-outline-primary btn-sm" onClick="backfillips(this);">Backfill IP addresses</button>
+        </span>
+    </div>
+</div>
 <hr>
 <p></p>
 <table id="nodes" class="display" style="width:100%">