Resolve #3352294 "Add admin templates page"

Closes #3352294

css/unione.templates.css

+.unione-template-item table.nl-container {
+  border: none;
+  outline: none;
+}
+
+.unione-template-item table.nl-container tr td table.row,
+.unione-template-item table.nl-container table.row table.row-content {
+  margin-top: 0;
+  margin-bottom: 0;
+}
+
+.unione-template-item table.nl-container tbody,
+.unione-template-item table.nl-container tr,
+.unione-template-item table.nl-container td {
+  border: none;
+  outline: none;
+  margin: 0;
+}
+
+.unione-template-item table.nl-container * {
+  pointer-events: none;
+}