fest: add stop method

src/node.ts

@@ -69,6 +69,10 @@ export class S5Node {
     await p2p.start();
   }
 
+  public async stop() {
+    await this.services.p2p.stop();
+  }
+
   async readStorageLocationsFromDB(
     hash: Multihash,
   ): Promise<Map<number, Map<string, Map<number, any>>>> {

src/service/p2p.ts

@@ -97,6 +97,9 @@ export class P2PService extends EventEmitter {
       this.connectToNode([new URL(p)]);
     }
   }
+  async stop() {
+    [...this.node.services.p2p.peers.values()].forEach((peer) => peer.end());
+  }
 
   async onNewPeer(peer: Peer, verifyId: boolean): Promise<void> {
     peer.challenge = crypto.randomBytes(32);