Restore correct wxSearchCtrl size in wxMSW after wxTextCtrl changes.

Restore correct wxSearchCtrl size in wxMSW after wxTextCtrl changes.

The code in generic wxSearchCtrl implementation was broken by the changes of
r69066 which deccreased the best height of border-less text controls.

Ideally we should probably change wxSearchCtrl::LayoutControls() to not be
sensitive at all to the exact value returned from wxTextCtrl::GetBestSize()
and just always centre everything vertically but this doesn't look simple to
do with the current code so just override wxSearchTextCtrl::DoGetBestSize() to
return the same size as wxTextCtrl used to return before to fix this for now.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@69284 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775