Add an option that controls page breaks in the PDF document

[RomanTsukanov]

Now, when we export a survey, we insert page breaks where a survey page ends. However, survey pages do not always fit into document pages. As a result, the document contains blank spaces that a reader may interpret as the end of the document. We can add an option that will control whether to insert survey page breaks into the document. Draft name: exportPageBreaks: true | false