feat(sol-keyring): change signing transaction interface

babel.config.js

@@ -0,0 +1,4 @@
+module.exports = {
+  presets: [['@babel/preset-env', { targets: { node: 'current' } }], '@babel/preset-typescript'],
+  plugins: ['@babel/plugin-proposal-optional-chaining']
+};

packages/sol-keyring/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@keystonehq/sol-keyring",
-  "version": "0.19.3",
+  "version": "1.0.0",
   "description": "sol-keyring interact with keystone",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

packages/sol-keyring/src/BaseKeyring.ts

@@ -1,6 +1,6 @@
 import bs58 from "bs58";
 import * as uuid from "uuid";
-import { Message, PublicKey, Transaction } from "@solana/web3.js";
+import { Message, Transaction } from "@solana/web3.js";
 import { InteractionProvider } from "./InteractionProvider";
 import { CryptoMultiAccounts } from "@keystonehq/bc-ur-registry";
 import { SolSignRequest, SignType } from "@keystonehq/bc-ur-registry-sol";
@@ -114,14 +114,13 @@ export class BaseKeyring {
     return this.keys;
   }
 
-  async signTransaction(pubKey: string, tx: Transaction): Promise<Transaction> {
+  async signTransaction(pubKey: string, txHex: Uint8Array): Promise<Uint8Array> {
     const signature = await this._getSignature(
       pubKey,
-      Buffer.from(tx.serializeMessage() as unknown as ArrayBuffer),
+      Buffer.from(txHex),
       SignType.Transaction
     );
-    tx.addSignature(new PublicKey(pubKey), signature);
-    return tx;
+    return signature;
   }
 
   async signMessage(