Make heap_page_is_all_visible independent of LVRelState

Make heap_page_is_all_visible independent of LVRelState

This function only requires a few fields from LVRelState, so pass them
in individually.

This change allows calling heap_page_is_all_visible() from code such as
pruneheap.c, which does not have access to an LVRelState.

Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/2wk7jo4m4qwh5sn33pfgerdjfujebbccsmmlownybddbh6nawl%40mdyyqpqzxjek