prf: provide plugin hook even for tables with 0 rows

datasette/templates/_table.html

@@ -1,7 +1,7 @@
+<!-- above-table-panel is a hook node for plugins to attach to . Displays even if no data available -->
+<div class="above-table-panel"> </div>
 {% if display_rows %}
 <div class="table-wrapper">
-    <!-- above-table-panel is a hook node for plugins to attach to  -->
-    <div class="above-table-panel"> </div>
     <table class="rows-and-columns">
         <thead>
             <tr>