Remove obsolete reports show_<format> actions
Remove obsolete reports show_<format> actions

a4b4147b026f eliminated the `button` action, which delegated to these
methods, but they were never removed with it.
(transferred from ManageIQ/manageiq@54d6391333533bb8db7835591403b9fdb05bbc60)

ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic