keyboxd: Extend PUBKEY_INFO status line with an uid ordinal.

* kbx/backend-sqlite.c (table_definitions): Add column UINO to
userids.
(be_sqlite_local_s): Add fields select_col_uidno and
select_col_subkey.
(run_select_statement): Also select subkey or uidno column.
(be_sqlite_search): Return their values.
(store_into_userid): Store the UIDNO.
* kbx/backend-support.c (be_return_pubkey): Extend PUBKEY_INFO.
--

For an existing database adding the new column to the table userid is
straightforward.  However if the original version of the schema used an
integer for the keyid column, that column has likely be renamed.  Make
sure that the NOT NULL constraint has also be removed; check the
SQLite documentation on how this can be done.

Signed-off-by: Werner Koch <wk@gnupg.org>

doc/DETAILS

@@ -1171,7 +1171,7 @@ pkd:0:1024:B665B1435F4C2 .... FF26ABB:
    Status codes are also used between the components of the GnuPG
    system via the Assuan S lines.  Some of them are documented here:
 
-*** PUBKEY_INFO <n> <ubid> <flags>
+*** PUBKEY_INFO <n> <ubid> <flags> <uidno> <pkno>
     The type of the public key in the following D-lines or
     communicated via a pipe.  <n> is the value of =enum pubkey_types=
     and <ubid> the Unique Blob ID (UBID) which is the fingerprint of
@@ -1183,6 +1183,10 @@ pkd:0:1024:B665B1435F4C2 .... FF26ABB:
     byte is either '-' for standard key or 'e' for an ephemeral key.
     The second byte is either '-' or 'r' for a known revoked key.
 
+    <uidno> and <pkno> are the ordinal numbers for the the user id or
+    public key which matches the search criteria.  A value of 0 means
+    not known.
+
 *** KEYPAIRINFO <grip> <keyref> [<usage>] [<keytime>] [<algostr>]
 
     This status is emitted by scdaemon and gpg-agent to convey brief