Group plan landing page (#10222)

* Updated task page styles

* Added initial page styles

* Added login and payments

* Updated more styles

* Added white header

* Added group plan overview modal

* Updated copy

* Fixed location

* Style updates

* Added analytics

* More style updates

* Added locales

* Removed duplicate key

website/client/components/groups/groupPlan.vue

@@ -342,7 +342,6 @@ export default {
         UPGRADE_GROUP: 'upgrade-group',
         PAY: 'pay',
       },
-      // @TODO: Import from payment library?
       PAYMENTS: {
         AMAZON: 'amazon',
         STRIPE: 'stripe',