Amend booking process to use this profile not hard coded field

Second of Three Jira Issues to stop the Email address being a required field during event registration if a profile has been assigned for the sign up process.

At present CiviCRM forces in the email address to the events booking process. If the email address is also included in the profile added to the booking process then the email address is removed out of the profile form.

CiviCRM should be amended so that instead of adding the single email address field into the form it adds the system profile created in http://issues.civicrm.org/jira/browse/CRM-9582.

Code changes will be to the following routines within the CiviCRM module
• CRM\Event\Form\Registration\Register.php
• CRM\Event\Form\Registration\AdditionalParticipant.php
• CRM\Event\Form\Registration\Confirm.php
• CRM\Event\BAO\Event.php
• CRM\Event\BAO\Participant.php

Test Cases

• Confirmation email sent to the correct email address
• Profile email address is carried through all pages, from booking form through to thank you and confirmation email content
• Contact email address set as entered and is set to primary if new contact

• Reserved email profile is also injected in Additional Participant forms if "register multiple participants" is enabled
  • De-Duplication is used when the email address is entered (uses default Individual Strict dedupe rule)
• If default individual strict rule is modified to dedupe based on first + last names or other rules, that deduping works as configured (want to make sure that organizations who configure events to not collect email address have a working contact matching option if desired - else each registration will ALWAYS create a new contact record)