common: New function to uncompress an ECC public key.
* common/sexputil.c (ec2os): New. (uncompress_ecc_q_in_canon_sexp): New. * common/t-sexputil.c (fail2): new. (test_ecc_uncompress): New. (main): Run new test.
(cherry picked from commit 935765b451aadc63fbba763a4a00f4efa0254436)
- Signed-off-by: Werner Koch <wk@gnupg.org>