* Add 2 new uno command aliases to handle 2 different
  styles of redaction export/sanitization:
    * .uno:RedactedExportBlack & .uno:RedactedExportWhite

* Replace the single export button with the 2 new buttons

* Add a new toolbox names .uno:RedactedExportToolbox which
  consists of the new 2 commands. It will be added to the Redaction
  toolbar after we solve the icon issue.

* Now new redaction shapes are named as RectangleRedactionShape
  or FreeformRedactionShape based on their type.

* While exporting to PDF, a seamless step of "Sanitization"
  takes place, in which, all shapes in the Draw doc are traversed
  and turned into opaq black or white (with black border) shapes,
  then the whole doc is converted into bitmap (page by page).

* After the export operation is completed. All shapes are converted
  back to the usual redaction style (gray and transparent).

* Icon issue:
  * We need 2 new icons for our new commands, one for black redaction
    shapes without border, and one for white redaction shapes with black
    border.
  * I tried adding links to a current icon, but it didn't work, so they
    are iconless for now.

* Next to do: Handle icon issue, and take the redaction implementation
  into a separate helper class because it is growing fast.

Change-Id: I9b2b7716289b800cdbe7bf3ffa4a442fe5afc474
Reviewed-on: https://gerrit.libreoffice.org/68072
Tested-by: Jenkins
Reviewed-by: Muhammet Kara <muhammet.kara@collabora.com>