Added tier type in API response

refs https://github.com/TryGhost/Team/issues/1037

Tiers now have a `type` column to differentiate between `free` and `paid` tiers. This change allows `type` data for a tier in Admin and Portal API output.

core/server/api/canary/utils/serializers/output/products.js

@@ -73,6 +73,7 @@ function serializeProduct(product, options, apiType) {
         name: json.name,
         description: json.description,
         slug: json.slug,
+        type: json.type,
         created_at: json.created_at,
         updated_at: json.updated_at,
         stripe_prices: json.stripePrices ? json.stripePrices.map(price => serializeStripePrice(price, hideStripeData)) : null,

core/server/services/members/middleware.js

@@ -109,6 +109,7 @@ const getPortalProductPrices = async function () {
             monthlyPrice: product.monthlyPrice,
             yearlyPrice: product.yearlyPrice,
             benefits: product.benefits,
+            type: product.type,
             prices: productPrices
         };
     });