ui: Gives the minimal in-form token list use a maximum row size (#5807)

This means its more straightforwards to calculate the height of the
listing itself. This component is currently only used on the form pages for tokens and roles, should therefore be a restricted size.

ui-v2/app/templates/components/token-list.hbs

@@ -3,6 +3,7 @@
   {{#tabular-collection
       data-test-tokens
       class='token-list'
+      rows=5
       items=(sort-by 'AccessorID:asc' items) as |item index|
   }}
   {{#if caption}}