Also changed the fill color of "Data" button to a lighter shade
to distiguish it from other buttons, for both row and column fields.

Added matching testcase in chart2dump.cxx

Change-Id: I2ae5da6c3552372f606da41055f1e0663b6f0802
Reviewed-on: https://gerrit.libreoffice.org/39687Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>