Lean optimize estimate

[Martin-Molinero]

• There's currently no way to estimate a local optimization execution. This functionality should first be added to Lean itself see https://github.com/QuantConnect/Lean/tree/master/Optimizer.Launcher The lean CLI should give Lean an estimate of how long a backtest takes, it could check the backtest folder for the lastest backtest run in that project, if none has been run we can ask the user to run one first, like the cloud requires