As a WCM admin, I would like to create a structure with a field that points to another WCM article

• Type: Story
• Status: Closed
• Priority: Critical
• Resolution: Completed
• Affects Version/s: None
• Fix Version/s: Master
• Component/s: Dynamic Data Mapping, Dynamic Data Mapping > Form Builder, Forms
• Labels:
  • QA-AUTOMATION
  • boa
• Sprint: Sprint 15: Apr, 18 - Apr, 29
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/38865

This should be similar to the document library link element. The field structure field will contain a pointer to a WC article and the actual linking will be done in the template.

Steps to reproduce:

1. Add a new structure with a Web Content field
2. add a template for the structure (use the web content field on this template)
3. create a web content with the structure and select a web content for the web content field.

Expected:

1. the web content selected for the field should appear as a JSON
   something like: {"className":"com.liferay.journal.model.JournalArticle","classPK":"34312"}

The JSON provided by the template must have enough info so the web content can be fetched and used by some other service.