Remove xloginsert.h from xlog.h

xlog.h is directly and indirectly #included in a lot of places.  With
this change, xloginsert.h is no longer unnecessarily included in the
large number of them that don't need it.

Author: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Discussion: https://postgr.es/m/CALj2ACVe-W+WM5P44N7eG9C2_FmaeM8Dq5aCnD3fHt0Ba=WR6w@mail.gmail.com

src/backend/access/heap/pruneheap.c

@@ -19,6 +19,7 @@
 #include "access/htup_details.h"
 #include "access/transam.h"
 #include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "catalog/catalog.h"
 #include "miscadmin.h"
 #include "pgstat.h"

src/backend/access/heap/vacuumlazy.c

@@ -44,6 +44,7 @@
 #include "access/visibilitymap.h"
 #include "access/xact.h"
 #include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "catalog/index.h"
 #include "catalog/storage.h"
 #include "commands/dbcommands.h"

src/backend/access/heap/visibilitymap.c

@@ -88,6 +88,7 @@
 
 #include "access/heapam_xlog.h"
 #include "access/visibilitymap.h"
+#include "access/xloginsert.h"
 #include "access/xlogutils.h"
 #include "miscadmin.h"
 #include "port/pg_bitutils.h"