Add vty command to show summary of all or filtered subscribers

Adds the following commands:

show subscribers all - Display summary of all entries in HLR
show subscribers (imsi|msisdn|cs|ps) ... As above but filter on search field/string
show subscribers last seen - Display only subscribers with data in
Last LU update field, and sorts by Last LU.

Change-Id: I7f0573381a6d0d13841ac6d42d50f0e8389decf4
diff --git a/include/osmocom/hlr/db.h b/include/osmocom/hlr/db.h
index ca336a0..f70df83 100644
--- a/include/osmocom/hlr/db.h
+++ b/include/osmocom/hlr/db.h
@@ -8,6 +8,12 @@
 struct hlr;
 
 enum stmt_idx {
+	DB_STMT_SEL_ALL,
+	DB_STMT_SEL_ALL_ORDER_LAST_SEEN,
+	DB_STMT_SEL_FILTER_MSISDN,
+	DB_STMT_SEL_FILTER_IMSI,
+	DB_STMT_SEL_FILTER_CS,
+	DB_STMT_SEL_FILTER_PS,
 	DB_STMT_SEL_BY_IMSI,
 	DB_STMT_SEL_BY_MSISDN,
 	DB_STMT_SEL_BY_ID,
@@ -148,6 +154,9 @@
 int db_subscr_exists_by_imsi(struct db_context *dbc, const char *imsi);
 int db_subscr_exists_by_msisdn(struct db_context *dbc, const char *msisdn);
 
+int db_subscrs_get(struct db_context *dbc, const char *filter_type, const char *filter,
+		   void (*get_cb)(struct hlr_subscriber *subscr, void *data), void *data,
+		   int *count, const char **err);
 int db_subscr_get_by_imsi(struct db_context *dbc, const char *imsi,
 			  struct hlr_subscriber *subscr);
 int db_subscr_get_by_msisdn(struct db_context *dbc, const char *msisdn,