[Experience Fragment] Add XF Page component

## Feature Request

**Is your feature request related to a problem? Please describe.**
When attempting to create a new experience fragment for a customer, discovered that experience fragment templates require referencing /libs/cq/experience-fragments/components/xfpage. This then references the OOTB WCM page component. Unable to use the core page component as there is functional changes between a full page handling and one that seeds XF templates.

**Describe the solution you'd like**
Addition of a new xfpage component that can be used to seed new XF templates.

**Are there alternatives?**
Continue to use the OOTB xfpage from libs, however this would be counter-productive to intent of core components.

**Documentation**
When configuring a new template-type, the associated proxy for this xfpage would be referenced in the /initial/jcr:content/@sling:resourceType property. The /structure/jcr:content/@sling:resourceType property would still reference the proxy for the page core component.

Start by reviewing the referenced /libs/cq/experience-fragments/components/xfpage and the OOTB WCM page component to understand the distinction between XF template seeding and full-page handling. The work is done when a new xfpage component can be used for the template-type/initial resourceType while template-type/structure continues to use the page component proxy.

Written by the indexing model from the issue text.