Adds GDPR shortcode which can be used in WordPress to display the GDPR update preferences form
Created by: agileware-justin
This PR adds a WordPress filter to expose GDPR page as shortcode for WordPress sites.
The capability to add user-defined shortcodes to CiviCRM was added in https://github.com/civicrm/civicrm-wordpress/pull/134
Agileware Ref: CIVIGDPR-5