Fix handling of fast clicks in wxRibbonBar under MSW.

Second click can result in a double click event instead of the usual simple
click if it happens quickly enough after the first one, so handle double
clicks in the same way as simple clicks instead of ignoring them.

Closes #16551.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@78322 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Make disabling submenus work in wxMSW.

As submenu items don't have a valid ID, we need to address them by their
position when calling EnableMenuItem() -- and for simplicity do it for all the
items.

Closes #16747.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@78323 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775