postgres: add itest

go.mod

@@ -24,6 +24,7 @@ require (
 	github.com/grpc-ecosystem/go-grpc-middleware v1.3.0
 	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.5.0
+	github.com/jackc/pgx/v4 v4.13.0
 	github.com/jackpal/gateway v1.0.5
 	github.com/jackpal/go-nat-pmp v0.0.0-20170405195558-28a68d0c24ad
 	github.com/jedib0t/go-pretty v4.3.0+incompatible