Avoid style issues with Turbo

But the filter dropdowns still get duplicated. So weird..

app/views/admin/products_v3/index.html.haml

@@ -1,5 +1,3 @@
-- content_for :body_class do
-  products_v3_page
 - content_for :page_title do
   = t('.header.title')
 - content_for :page_actions do

app/webpacker/css/admin/products_v3.scss

@@ -1,5 +1,6 @@
 // Customisations for the new Bulk Edit Products page only
-.products_v3_page {
+// Scoped to containing div, because Turbo messes with body classes
+#products_v3_page {
   #content > .row:first-child > .container:first-child {
     // Allow table to extend to full width of available screen space
     // TODO: move this to a generic rule, eg body.full-width{}. Then it can be included on any page.