Addition of the skeleton of the new SF_Writer service as a subclass of SF_Document. Entry points in CreateScriptService are provided both for Basic and Python user scripts. Full compatibility with existing user scripts. Specific properties and methods will be provided in later commits. Change-Id: Ib00a9ea52023707d1429e8ad9dcb4dca2ca63174 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/118515 Tested-by: Jean-Pierre Ledure <jp@ledure.be> Tested-by: Jenkins Reviewed-by: Jean-Pierre Ledure <jp@ledure.be>