Add makeTx function with NetworkProvider interface

Related to #2617

---

For more details, open the [Copilot Workspace session](https://copilot-workspace.githubnext.com/planetarium/lib9c/issues/2617?shareId=XXXX-XXXX-XXXX-XXXX).

integrations/javascript/@planetarium/lib9c/README.md

@@ -3,3 +3,20 @@
 This npm package provides functions to build actions equivalent to [Lib9c].
 
 [Lib9c]: https://github.com/planetarium/lib9c
+
+## Usage Example
+
+```typescript
+import { HeadlessNetworkProvider } from "@planetarium/9c-headless-network-provider";
+import { RawPrivateKey, Address } from "@planetarium/account";
+import { makeTx, ClaimStakeReward } from "@planetarium/lib9c";
+
+const networkProvider = new HeadlessNetworkProvider("https://9c-main-full-state.nine-chronicles.com/graphql");
+const account = RawPrivateKey.generate();  // Temporary private key key.
+
+const unsignedTx = await makeTx(account, networkProvider, new ClaimStakeReward({
+  avatarAddress: Address.fromHex('<ADDRESS>'),
+}));
+
+console.log(unsignedTx);
+```

integrations/javascript/@planetarium/lib9c/src/index.ts

@@ -64,3 +64,4 @@ export {
   type MigratePledgeToGuildArgs,
 } from "./actions/migrate_pledge_to_guild.js";
 export { MakeGuild } from "./actions/make_guild.js";
+export { makeTx, type NetworkProvider } from "./tx.js";

integrations/javascript/@planetarium/lib9c/src/tx.ts

@@ -0,0 +1,24 @@
+import { Account, Address } from '@planetarium/account';
+import { UnsignedTx } from '@planetarium/tx';
+import { PolymorphicAction } from './actions/common.js';
+
+export interface NetworkProvider {
+  getNextNonce(address: Address): Promise<bigint>;
+  getGenesisHash(): Promise<string>;
+}
+
+export async function makeTx(
+  account: Account,
+  provider: NetworkProvider,
+  action: PolymorphicAction
+): Promise<UnsignedTx> {
+  const nonce = await provider.getNextNonce(account.address);
+  const genesisHash = await provider.getGenesisHash();
+
+  return new UnsignedTx({
+    nonce,
+    genesisHash,
+    signer: account,
+    actions: [action],
+  });
+}