tableam: Rename wrapper functions to match callback names.

Some of the wrapper functions didn't match the callback names. Many of
them due to staying "consistent" with historic naming of the wrapped
functionality. We decided that for most cases it's more important to
be for tableam to be consistent going forward, than with the past.

The one exception is beginscan/endscan/...  because it'd have looked
odd to have systable_beginscan/endscan/... with a different naming
scheme, and changing the systable_* APIs would have caused way too
much churn (including breaking a lot of external users).

Author: Ashwin Agrawal, with some small additions by Andres Freund
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/CALfoeiugyrXZfX7n0ORCa4L-m834dzmaE8eFdbNR6PMpetU4Ww@mail.gmail.com

src/backend/executor/execMain.c

@@ -2436,7 +2436,7 @@ ExecBuildAuxRowMark(ExecRowMark *erm, List *targetlist)
  * quals. For that result to be useful, typically the input tuple has to be
  * last row version (otherwise the result isn't particularly useful) and
  * locked (otherwise the result might be out of date). That's typically
- * achieved by using table_lock_tuple() with the
+ * achieved by using table_tuple_lock() with the
  * TUPLE_LOCK_FLAG_FIND_LAST_VERSION flag.
  *
  * Returns a slot containing the new candidate update/delete tuple, or
@@ -2654,9 +2654,9 @@ EvalPlanQualFetchRowMarks(EPQState *epqstate)
 			else
 			{
 				/* ordinary table, fetch the tuple */
-				if (!table_fetch_row_version(erm->relation,
-											 (ItemPointer) DatumGetPointer(datum),
-											 SnapshotAny, slot))
+				if (!table_tuple_fetch_row_version(erm->relation,
+												   (ItemPointer) DatumGetPointer(datum),
+												   SnapshotAny, slot))
 					elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
 			}
 		}