Make sure row numbers stay vertically aligned

Just looks tidier.

app/assets/stylesheets/components/table.scss

@@ -74,6 +74,12 @@
 
   }
 
+  &-invisible-error {
+    border-left: 5px solid transparent;
+    padding-left: 7px;
+    display: block;
+  }
+
   &-status {
 
     &-default {

app/templates/views/check.html

@@ -188,7 +188,7 @@
       caption=original_file_name,
       caption_visible=False,
       field_headings=[
-        '<span class="visually-hidden">Row in file</span><span aria-hidden="true">1</span>'|safe
+        '<span class="visually-hidden">Row in file</span><span aria-hidden="true" class="{}">1</span>'.format("table-field-invisible-error" if errors else "")|safe
       ] + recipients.column_headers
     ) %}
       {% call index_field() %}