feat: implement export functionality for projects and scenarios with CSV and Excel support

templates/partials/import_preview_table.html

@@ -0,0 +1,17 @@
+{% from "partials/components.html" import table_container %}
+
+{% call table_container("import-preview-container", hidden=True, aria_label="Import preview table", heading=table_heading or "Preview Rows") %}
+  <thead>
+    <tr>
+      <th scope="col">Row</th>
+      <th scope="col">Status</th>
+      <th scope="col">Issues</th>
+      {% for column in columns %}
+      <th scope="col">{{ column }}</th>
+      {% endfor %}
+    </tr>
+  </thead>
+  <tbody data-import-preview-body>
+    <!-- Rows injected via JavaScript -->
+  </tbody>
+{% endcall %}