listinvoice: populate local_offer_id when iterating whole db.

And add the local_offer_id to the schemas too.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-EXPERIMENTAL: JSONRPC: `listoffers` now shows `local_offer_id` when listing all offers.

wallet/invoices.c

@@ -455,6 +455,7 @@ bool invoices_iterate(struct invoices *invoices,
 						       ", bolt11"
 						       ", description"
 						       ", features"
+						       ", local_offer_id"
 						       " FROM invoices"
 						       " ORDER BY id;"));
 		db_query_prepared(stmt);