chore: Update Help Center APIs to accomodate locale (#4515)

db/migrate/20220416203340_add_config_to_portal.rb

@@ -0,0 +1,5 @@
+class AddConfigToPortal < ActiveRecord::Migration[6.1]
+  def change
+    add_column :kbase_portals, :config, :jsonb, default: { allowed_locales: ['en'] }
+  end
+end

db/migrate/20220416205519_add_locale_to_kbase_category.rb

@@ -0,0 +1,7 @@
+class AddLocaleToKbaseCategory < ActiveRecord::Migration[6.1]
+  def change
+    add_column :kbase_categories, :locale, :string, default: 'en'
+    add_index :kbase_categories, :locale
+    add_index :kbase_categories, [:locale, :account_id]
+  end
+end