Fixed popup menu's title to be bold regardless of method used.

Fixed popup menu's title to be bold regardless of method used.

Popup menus with title set via SetTitle() had bold font, but menus
created by passing title as ctor argument used normal font. Fixed this
by using the same code (SetTitle) in both cases, instead of having two
independent (and out of sync) implementations of the same functionality.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@64255 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775