Move PG_TEMP_FILE* macros to file_utils.h.

Presently, frontend code that needs to use these macros must either
include storage/fd.h, which declares several frontend-unsafe
functions, or duplicate the macros.  This commit moves these macros
to common/file_utils.h, which is safe for both frontend and backend
code.  Consequently, we can also remove the duplicated macros in
pg_checksums and stop including storage/fd.h in pg_rewind.

Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/ZOP5qoUualu5xl2Z%40paquier.xyz

src/backend/storage/file/fileset.c

@@ -25,6 +25,7 @@
 
 #include "catalog/pg_tablespace.h"
 #include "commands/tablespace.h"
+#include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "miscadmin.h"
 #include "storage/ipc.h"