These include
  - Author
  - Page Count
  - Page Name
Export and import of slide number was already implemented. A test
for the same has been added along with the tests for the newly
implemented field exports.

In sdmodeltestbase.hxx a new method getTextFieldFromPage has been
added to reduce copy-paste code

Change-Id: Icf54b91a7db4b3cccd9d0666a2706e3cc2a89d9a
Reviewed-on: https://gerrit.libreoffice.org/22065Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>