Got book to shelf conversions working

- Also extracted shelf to book view elements to own partial.
- Fixed some existing logic including image param handling in update
  request and activity logging against correct element.

app/Actions/ActivityType.php

@@ -22,6 +22,7 @@ class ActivityType
     const BOOK_SORT = 'book_sort';
 
     const BOOKSHELF_CREATE = 'bookshelf_create';
+    const BOOKSHELF_CREATE_FROM_BOOK = 'bookshelf_create_from_book';
     const BOOKSHELF_UPDATE = 'bookshelf_update';
     const BOOKSHELF_DELETE = 'bookshelf_delete';