qt: List keys once with --with-secret instead of twice
* lang/qt/src/qgpgmelistallkeysjob.cpp (do_list_keys): Rename to do_list_keys_legacy and put into unnamed namespace. (merge_keys): Put into unnamed namespace. (list_keys): Rename to list_keys_legacy and put into unnamed namespace. (do_list_keys, list_keys): New. * lang/qt/tests/t-keylist.cpp (testListAllKeysSync): New.
With gpg >= 2.1, list keys once with --with-secret instead of listing
public keys and secret keys and then merging (part of) the information
about the keys.
- GnuPG-bug-id: T4794