Bitcoinjs (#20556)

* added inputs to transaction builder

* verify should return boolean, fixed inputs

* added property private key (d) in ECPair class

types/bitcoinjs-lib/index.d.ts

@@ -66,6 +66,8 @@ export class ECPair {
 
     constructor(d: null | undefined, Q: any, options?: { compressed?: boolean, network?: Network }); // Q should be ECPoint, but not sure how to define such type
 
+    d: BigInteger;
+
     getAddress(): string;
 
     getNetwork(): Network;