PR64: Various Phoenix and Py3 fixes for the demo and library

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@75720 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix a missed wx.ArtProvider_GetBitmap to wx.ArtProvider.GetBitmap change.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@75721 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775