Add name attribute to Payments

ts_src/payments/p2ms.ts

@@ -102,6 +102,10 @@ export function p2ms(a: Payment, opts?: PaymentOpts): Payment {
     if (!o.input) return;
     return [];
   });
+  lazy.prop(o, 'name', () => {
+    if (!o.m || !o.n) return;
+    return `p2ms(${o.m} of ${o.n})`;
+  });
 
   // extended validation
   if (opts.validate) {