feat: APIs for Articles (#4777)

Fixes: #4802

app/views/api/v1/accounts/articles/_article.json.jbuilder

@@ -0,0 +1,20 @@
+json.id article.id
+json.category_id article.category_id
+json.title article.title
+json.content article.content
+json.description article.description
+json.status article.status
+json.account_id article.account_id
+
+if article.portal.present?
+  json.portal do
+    json.partial! 'api/v1/accounts/portals/portal.json.jbuilder', portal: article.portal
+  end
+end
+json.views article.views
+
+if article.author.present?
+  json.author do
+    json.partial! 'api/v1/models/agent.json.jbuilder', resource: article.author
+  end
+end