fix: deserialization and verification of payment paths (#1382)

Fixes #1347

Ref #1376

snippets/src/paths.ts

@@ -0,0 +1,47 @@
+import {RippleAPI} from '../../dist/npm'
+
+const api = new RippleAPI({
+  // server: 'wss://s.altnet.rippletest.net:51233'
+  server: 'ws://35.158.96.209:51233'
+  // 34.210.87.206
+})
+
+sign()
+
+async function sign() {
+  await api.connect()
+  const pathfind: any = {
+    source: {
+      address: 'r9cZA1mLK5R5Am25ArfXFmqgNwjZgnfk59',
+      amount: {
+        currency: 'drops',
+        value: '100'
+      }
+    },
+    destination: {
+      address: 'rKT4JX4cCof6LcDYRz8o3rGRu7qxzZ2Zwj',
+      amount: {
+        currency: 'USD',
+        counterparty: 'rVnYNK9yuxBz4uP8zC8LEFokM2nqH3poc'
+      }
+    }
+  }
+
+  await api.getPaths(pathfind).then(async (data) => {
+    console.log('paths:', JSON.stringify(data))
+    const fakeSecret = 'shsWGZcmZz6YsWWmcnpfr6fLTdtFV'
+
+    pathfind.paths = data[0].paths
+    pathfind.destination = data[0].destination
+    await api.preparePayment('r9cZA1mLK5R5Am25ArfXFmqgNwjZgnfk59', pathfind).then(ret => {
+      const signed = api.sign(ret.txJSON, fakeSecret)
+      console.log('signed:', signed)
+    }).catch(err => {
+        console.log('ERR 1:', JSON.stringify(err))
+    })
+  }).catch(err => {
+      console.log('ERR 2:', err)
+  })
+
+  api.disconnect()
+}