CORE-18336
The current design was not processing actions verbs correctly for some
Start Menu context menu actions (Properties, Open all users, Explore all users),
despite associated code being implemented.
This was due by incorrectly filtering command IDs, not routing to the appropriate processing.
-Rename StartMenuBtnCtxMenuCreator to CStartMenuBtnCtxMenu_CreateInstance.
-Rename CreateStartMenuSite to CStartMenuSite_CreateInstance.
-Remove a couple of definitions that were not used.