Optionally show standard "Help" question mark button in the ribbon top right
corner and generate the appropriate event for it.
Closes#14576.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72495 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Show the "extension button" in the ribbon panel if this style is specified.
Also generate a specific event if this button is clicked.
Closes#14283.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71642 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
