Revert "Optimize pg_visibility with read streams."
This reverts commit
ed1b1ee59fb3792baa32f669333b75024ef01bcc and its
followup
1c61fd8b527954f0ec522e5e60a11ce82628b681. They rendered
collect_corrupt_items() unable to detect corruption.
Discussion: https://postgr.es/m/CAN55FZ1_Ru3XpMgTwsU67FTH2fs_FrRROmb7x6zs+F44QBEiww@mail.gmail.com
Discussion: https://postgr.es/m/CAEudQAozv3wTY5TV2t29JcwPydbmKbiWQkZD42S2OgzdixPMDQ@mail.gmail.com