wallet: Add tooling to extract SQL queries and generate driver info

This is the counterpart of the annotations we did in the last few commits. It
extracts queries, passes them through a driver-specific query rewriter and
dumps them into a driver-specific query-list, along with some metadata to
facilitate processing later on. The generated query list is then registered as
a `db_config` and will be loaded by the driver upon instantiation.

Signed-off-by: Christian Decker <decker.christian@gmail.com>

wallet/db_sqlite3.c

@@ -0,0 +1,13 @@
+#include <wallet/db_common.h>
+#include "gen_db_sqlite3.c"
+#if HAVE_SQLITE3
+
+struct db_config db_sqlite3_config = {
+	.name = "sqlite3",
+	.queries = db_sqlite3_queries,
+	.num_queries = DB_SQLITE3_QUERY_COUNT,
+};
+
+AUTODATA(db_backends, &db_sqlite3_config);
+
+#endif