* g10/keyedit.c (find_userid_by_namehash, find_userid): New.
(keyedit_quick_revuid): Use find_userid() instead of iterating over the
nodes of the keyblock.
* tests/openpgp/quick-key-manipulation.scm: Add test for revoking a
user ID specified by its hash.
--
This makes it possible to specify the user ID to revoke as UID hash when
calling --quick-revoke-uid.
GnuPG-bug-id: 5936
(cherry picked from commit 35b17550706c8b7479ae96654feb97c05263cfc9)