Fix wxDC::DrawRectangle() when using RTL in wxMSW.

Extend the correct edge of the rectangle (always the physical right, not the
logical right) to fix off by one errors in RTL mode, affecting notably wxGrid.

See #16250.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@77027 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775