Due to a typo the size was expressed in 1/10th of a point and not in points.
Fix this and add a unit test checking that GetStyle() returns the same font as
was set by SetStyle().
Closes#2120.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70341 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775