Add CTAs to daily emails

Add a daily email CTA node type and reference field to attach a CTA to a
daily email.

Also update the RSS feed view to include the referenced body field
value.

config/sync/core.entity_view_display.node.daily_email.default.yml

@@ -4,6 +4,7 @@ status: true
 dependencies:
   config:
     - field.field.node.daily_email.body
+    - field.field.node.daily_email.field_daily_email_cta
     - node.type.daily_email
   module:
     - text
@@ -21,4 +22,5 @@ content:
     weight: 0
     region: content
 hidden:
+  field_daily_email_cta: true
   links: true