🐛(e2e) sync doc grid sorting check

The sorting check was not the same between
what django provide and what the e2e test
check, it was giving some flakiness.
Django seems to ignore the punctuation (space)
in its sorting.
We improve other test to be more robust
as well.

src/frontend/apps/e2e/__tests__/app-impress/common.ts

@@ -120,11 +120,13 @@ export const goToGridDoc = async (
   const header = page.locator('header').first();
   await header.locator('h2').getByText('Docs').click();
 
-  const rows = page
+  const datagrid = page
     .getByLabel('Datagrid of the documents page 1')
-    .getByRole('table')
-    .getByRole('row');
+    .getByRole('table');
 
+  await expect(datagrid.getByLabel('Loading data')).toBeHidden();
+
+  const rows = datagrid.getByRole('row');
   const row = title
     ? rows.filter({
         hasText: title,