wkd: Implement --blacklist option for gpg-wks-client
* tools/gpg-wks-client.c (blacklist_array, blacklist_array_len): New. (parse_arguments): Install blacklist. (read_file): New. (cmp_blacklist, add_blacklist, is_in_blacklist): New. (mirror_one_key): Check list. * tools/gpg-wks.h (opt): Remove field blacklist.
(cherry picked from commit b0b4e24c4fa80c10d310a229f5a0c65a57ad9393)
- GnuPG-bug-id: T6224