GSoC Blurry Shadow Weekly Update

Hello,
Sorry for the late report, I was busy this week with my last college exam
and I am finally free now.

I've tried to make time to work on the shadow blur preview in the area
dialog. I've tried to use ProcessAndBlurAlphaMask inside the paint
function[1] of the shadow preview but it didn't work.
Now, I think I should add XATTR_FILLBLUR for shadow blur to be added in
m_aXFillAttr [2], so it can be included in shadow attributes. I don't know
yet whether it's a right or wrong approach, I would really be grateful if
anyone could help.

I am willing to continue on the same task this week and I hope I can finish
it.

[1]:
https://opengrok.libreoffice.org/xref/core/svx/source/dialog/dlgctrl.cxx?r=9bef09cb#1241
[2]:
https://opengrok.libreoffice.org/xref/core/cui/source/tabpages/tpshadow.cxx?r=6dbfbeba#496

Regards,
Ahmad