Don't use standard menu ids in the unit test to avoid Mac problems.

Don't use standard menu ids in the unit test to avoid Mac problems.

wxOSX rearranges the standard menu items such as wxID_EXIT and wxID_ABOUT and,
for the former, changes its text to "Quit", so don't use them in the menu unit
test which expects to find the items in the menus to which they were added and
exactly with the labels used when adding them.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66144 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775