* Add an enum and some methods to DocumentToGraphicRenderer
  to differentiate between the doc/module types:
    isWriter(), isCalc(), isImpress()
* Put some checks for module/doc type
* The result seems ok for a Calc document of multiple sheets
  with hundreds of pages

Change-Id: Idf3e1966d4239df30a48a947a95c9085c25ee1bb
Reviewed-on: https://gerrit.libreoffice.org/66605
Tested-by: Jenkins
Reviewed-by: Muhammet Kara <muhammet.kara@collabora.com>