Restore support for using faster dotted pens in wxMSW

Changes of d245dc9e1f (Fix drawing of dotted lines with wxDC in wxMSW,
2020-03-27) improved the appearance of dotted and dashed lines in wxMSW
but at the expense of significant (up to a factor of 300) slowdown.

Allow the applications for which the drawing performance is important to
explicitly request the old behaviour, with uglier, but faster, pens by
choosing to use low quality pens.

Update the graphics benchmark to allow specifying the pen quality and
verify that the performance when using it is the same as before 3.1.4.

See https://github.com/wxWidgets/wxWidgets/pull/2218

See #7097.

Closes #18875.

docs/changes.txt

@@ -47,6 +47,11 @@ Changes in behaviour not resulting in compilation errors
   event handlers if you want the standard key combinations such as Alt-Space or
   Alt-F4 to work.
 
+- wxMSW port now uses better appearing but much slower pens for dotted and
+  dashed lines. Use wxPenInfo::LowQuality() or wxPen::SetQuality() to return to
+  the previous version behaviour and performance characteristics if you are
+  drawing many lines using such pens.
+
 - wxOSX port uses default button margins for wxBitmapButton by default, for
   consistency with the other ports. You now need to call SetMargins(0, 0)
   explicitly if you really don't want to have any margins in your buttons.