Improve integration with book module

Problem/Motivation

The book module provides a "printer-friendly" version of a book with all sub-nodes. It would be useful to make these features work better together

1. Use the same view mode
2. Combine the UI to open the printable

Proposed resolution

1. Allow selecting a different view mode for printable pages
2. Put the book link into the printable links named "print with child pages"

Remaining tasks

User interface changes

API changes

None

Data model changes

None