Make coordinates transformations in wxDC really maximally precise.

Make coordinates transformations in wxDC really maximally precise.

Use the maximal device space extent supported by Win32 GDI and only decrease
it if the scale is so small that keeping the device space extent maximal would
result in overflowing the int range for the logical space.

This makes coordinate translations exact even for huge coordinates, while they
could be significantly wrong before due to the integer rounding errors.

Closes #13284.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@68206 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775