common: New function cmp_canon_sexp.
* common/sexputil.c (cmp_canon_sexp): New. (cmp_canon_sexp_def_tcmp): New. * common/t-sexputil.c (test_cmp_canon_sexp): Add a simple test.
To be used to fix
- GnuPG-bug-id: T5061
- Signed-off-by: Werner Koch <wk@gnupg.org>