Harmonize parameter names in storage and AM code.

Harmonize parameter names in storage and AM code.

Make sure that function declarations use names that exactly match the
corresponding names from function definitions in storage, catalog,
access method, executor, and logical replication code, as well as in
miscellaneous utility/library code.

Like other recent commits that cleaned up function parameter names, this
commit was written with help from clang-tidy.  Later commits will do the
same for other parts of the codebase.

Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/CAH2-WznJt9CMM9KJTMjJh_zbL5hD9oX44qdJ4aqZtjFi-zA3Tg@mail.gmail.com