Remove locking during SaveResults in BacktestingResultHandler
Remove locking during SaveResults in BacktestingResultHandler

We now only lock for the time needed to create a copy of the charts.

jameschch/Lean,jameschch/Lean,jameschch/Lean,kaffeebrauer/Lean,Jay-Jay-D/LeanSTP,kaffeebrauer/Lean,QuantConnect/Lean,JKarathiya/Lean,StefanoRaggi/Lean,QuantConnect/Lean,AlexCatarino/Lean,QuantConnect/Lean,StefanoRaggi/Lean,QuantConnect/Lean,AlexCatarino/Lean,jameschch/Lean,jameschch/Lean,Jay-Jay-D/LeanSTP,JKarathiya/Lean,StefanoRaggi/Lean,Jay-Jay-D/LeanSTP,JKarathiya/Lean,Jay-Jay-D/LeanSTP,AlexCatarino/Lean,kaffeebrauer/Lean,StefanoRaggi/Lean,StefanoRaggi/Lean,Jay-Jay-D/LeanSTP,kaffeebrauer/Lean,AlexCatarino/Lean,kaffeebrauer/Lean,JKarathiya/Lean