Develop: Adjust mail view to show individual mail piece

[mdconatser]

As a user looking at a message from USPS informed delivery, I want to look at one individual piece of mail at a time with all its relevant content. This will let me better utilize the "Do more with your mail" functionality that USPS provides with those messages.

Acceptance Criteria

• Mail view operates based on the MailPiece data object
• Mail view shows the following sections in order:
  • MailPiece.Sender
  • Image of the mail piece (re-pulled using our email client library based on the MailPiece.EmailID and MailPiece.MID
  • Mail Actions panel (blank for now)
  • "Do more with your mail" segment for this mail piece (re-pulled using our email client library based on the MailPiece.EmailID and MailPiece.MID.
  • MailPiece.ImageText content
• Document any relevant content in the Programmer guide (draft thoughts of usage and importantly the "Why")
• Updates SRS and STP (and other docs if necessary)
• Add/Update relevant unit tests

[mdconatser]

If message no longer exists on the server (so no image or "do more" segments), just display some kind of warning message

[mdconatser]

tested on android