adding the warmup candles in front of the test period

[kakulukia]

The normal backtest is already doing that, but the research modules get_candles was missing such functionality.

[saleh-mir]

I prefer this idea over my previous one of passing warmup candles directly to the backtesting function. This new approach is simpler: you pass the number, and it provides the candles. If warmup candles are not passed, the function will handle it by splitting them. Just ensure we pass them initially, and it should work fine.

for future pull requests, please make sure that your pull request only includes the change the required code for this functionality It's really difficult for me to go through. It seems like it's been combined with your other previous pull requests.

[kakulukia]

Sorry for that! Next time just tell me to clean it up first. 🙈

[saleh-mir]

No problem ;)