tdf#128345 pptx export: add transparence gradient in solid fill

In case of solid color fill a transparence gradient was not saved.
OOXML has no separate element for gradient transparency but has
transparency in color gradient stop elements. The patch detects
a transparence gradient, combines it with the fill color and exports
it as gradFill element.
The import was already correct, besides a wrong start or end value
in case of a symmetric gradient, which becomes AXIAL in LibreOffice.

Change-Id: I4243656821629f90125d0408a38165a8a29e6e24
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/98792
Tested-by: Jenkins
Reviewed-by: Regina Henschel <rb.henschel@t-online.de>

0 files changed, 0 insertions, 0 deletions