add dropdown component for traditional or with export_template export

Co-authored-by: mfo <mfo@users.noreply.github.com>

spec/system/instructeurs/instruction_spec.rb

@@ -132,8 +132,9 @@ describe 'Instructing a dossier:', js: true do
     test_statut_bar(a_suivre: 1, tous_les_dossiers: 1)
 
     click_on "Télécharger un dossier"
-    within(:css, '.dossiers-export') do
-      click_on "Demander un export au format .csv"
+    within(:css, '#tabpanel-standard1-panel') do
+      choose "Fichier csv", allow_label_click: true
+      click_on "Demander l'export"
     end
 
     expect(page).to have_text('Nous générons cet export.')