Smarter "wait" for historical market data than a simple sleep?

Waiting for a set amount of seconds is a bit of a naive approach to waiting for data to come back from TWS. Is there a better way to wait/block code for, say, the `"msg": ""` when waiting for historical data? For this simple example, we can assume that we're wanting data for 1, synchronous request:

```
package main

import (
"time"

"github.com/hadrianl/ibapi"
)

func main() {
// internal api log is zap log, you could use GetLogger to get the logger
// besides, you could use SetAPILogger to set you own log option
// or you can just use the other logger
log := ibapi.GetLogger().Sugar()
defer log.Sync()

// implement your own IbWrapper to handle the msg delivered via tws or gateway
// Wrapper{} below is a default implement which just log the msg
ic := ibapi.NewIbClient(&ibapi.Wrapper{})

// tcp connect with tws or gateway
// fail if tws or gateway had not yet set the trust IP
if err := ic.Connect("127.0.0.1", 4002, 0); err != nil {
log.Panic("Connect failed:", err)
}

// handshake with tws or gateway, send handshake protocol to tell tws or gateway the version of client
// and receive the server version and connection time from tws or gateway.
// fail if someone else had already connected to tws or gateway with same clientID
if err := ic.HandShake(); err != nil {
log.Panic("HandShake failed:", err)
}

// Create a contract for SPY ETF
spyContract := ibapi.Contract{
Symbol: "SPY",
SecurityType: "STK",
Exchange: "SMART",
Currency: "USD",
}

// Set the request ID
reqID := ic.GetReqID()

// Get the contract details to ensure proper contract is created
// ic.ReqContractDetails(reqID, &spyContract)

// Request delayed market data for SPY
ic.ReqMarketDataType(3) // 3 or 4 for delayed, 1 when you have subscribed to real-time market data

// Request historical data for SPY
ic.ReqHistoricalData(reqID, &spyContract, time.Now().Format("20060102 15:04:05"), "1 W", "5 mins", "TRADES", false, 2, false, []ibapi.TagValue{})

ic.Run()

// Wait for a response (naive)
<-time.After(time.Second * 15)

// Wait for the log message {"level":"info","ts":1.......,"msg":"","reqID":1,"startDate":"20240101 19:32:40","endDate":"20240108 19:32:40"}
// i.e. "msg":"" is received
// ??????????

// Cancel the historical data request
ic.CancelHistoricalData(reqID)

ic.Disconnect()
}
```