Delegate UniverseManager methods to single impl
Delegate UniverseManager methods to single impl

Easy to introduce bugs when each method that is intended to do the same thing
implements it internally instead of delegating to a common implementation.
Also simplified syntax of invoking event handler

AlexCatarino/Lean,jameschch/Lean,StefanoRaggi/Lean,AlexCatarino/Lean,QuantConnect/Lean,StefanoRaggi/Lean,Jay-Jay-D/LeanSTP,AlexCatarino/Lean,AnshulYADAV007/Lean,JKarathiya/Lean,kaffeebrauer/Lean,AlexCatarino/Lean,jameschch/Lean,QuantConnect/Lean,AnshulYADAV007/Lean,StefanoRaggi/Lean,kaffeebrauer/Lean,AnshulYADAV007/Lean,QuantConnect/Lean,Jay-Jay-D/LeanSTP,StefanoRaggi/Lean,jameschch/Lean,jameschch/Lean,Jay-Jay-D/LeanSTP,AnshulYADAV007/Lean,Jay-Jay-D/LeanSTP,jameschch/Lean,JKarathiya/Lean,Jay-Jay-D/LeanSTP,QuantConnect/Lean,kaffeebrauer/Lean,AnshulYADAV007/Lean,JKarathiya/Lean,kaffeebrauer/Lean,StefanoRaggi/Lean,kaffeebrauer/Lean,JKarathiya/Lean