Add select/deselect all checkbox

There's A Controller For That.
(But I think it makes the HTML ugly..)

app/views/admin/dfc_product_imports/index.html.haml

@@ -12,13 +12,18 @@
   = form.hidden_field :enterprise_id, value: @enterprise.id
   = form.hidden_field :catalog_json, value: @catalog_json
 
-  %table
+  %table{"data-controller": "checked" }
+    %thead
+      %tr
+        %th
+          %input{ type: 'checkbox', title: t('.select_all'), 'aria-label': t('.select_all'), data: { "checked-target": "all", action: "change->checked#toggleAll" } }
+        %th
     %tbody
       - @items.each do |supplied_product, existing_product|
         %tr{id: supplied_product.semanticId }
           %td
             %label
-              = form.check_box 'semanticIds[]', { checked: true }, supplied_product.semanticId, ""
+              = form.check_box 'semanticIds[]', { checked: true, data: { "action" => "change->checked#toggleCheckbox", "checked-target" => "checkbox" } }, supplied_product.semanticId, ""
               = supplied_product.name
           %td
             - if existing_product.present?

config/locales/en.yml

@@ -851,6 +851,7 @@ en:
         title: "DFC product catalog"
         catalog_url: "%{count} products to be imported from: %{catalog_url}"
         enterprise: "Import to enterprise: %{enterprise_name}"
+        select_all: "Select/deselect all"
         update: Update
         new: New
         import: Import

spec/system/admin/dfc_product_import_spec.rb

@@ -65,7 +65,13 @@ RSpec.describe "DFC Product Import" do
     expect(page).to have_content "Beans - Case, 12 x 400g (can) New"
     expect(page).to have_content "Chia Seed, Organic - Retail pack, 300g"
 
-    uncheck "Chia Seed, Organic - Case, 8 x 300g" # don't import this one
+    # I can select all
+    uncheck "Chia Seed, Organic - Case, 8 x 300g"
+    check "Select/deselect all"
+    expect(page).to have_checked_field "Chia Seed, Organic - Case, 8 x 300g"
+
+    # And deselect one
+    uncheck "Chia Seed, Organic - Case, 8 x 300g"
 
     expect {
       click_button "Import"