web/satellite: Add router-view back to old billing page

When implementing the new billing screen, we mistakenly removed the
router-view component from the old billing screen. There was also an
issue where the button would add an extra /billing in the path, so this
change modifies the way the router navigates to the add-coupon route.

Change-Id: Iad3e9aea8c91dbf3bb13022e0995b24ade26af0d

web/satellite/src/components/account/billing/BillingArea.vue

@@ -34,7 +34,6 @@
                 </div>      
             </div>
             <div class="account-billing-area__divider" />
-            <router-view />
         </div>
         <div v-if="!isNewBillingScreen">
             <div v-if="hasNoCreditCard" class="account-billing-area__notification-container">
@@ -84,6 +83,7 @@
             <SmallDepositHistory />
             <CouponArea />
         </div>
+        <router-view />
     </div>
 </template>
 

web/satellite/src/components/account/billing/coupons/CouponArea.vue

@@ -96,7 +96,7 @@ export default class CouponArea extends Vue {
      */
     public onCreateClick(): void {
         this.analytics.pageVisit(RouteConfig.Billing.with(RouteConfig.AddCouponCode).path);
-        this.$router.push(RouteConfig.Billing.with(RouteConfig.AddCouponCode).path);
+        this.$router.push({ name: RouteConfig.AddCouponCode.name })
     }
 
     /**