RaceManager class (#562)

* Create RaceManager.cpp

* Create RaceManager class for race lifecycle management

Added RaceManager class to manage race events lifecycle.

* Refactor World class and implement ClearWorld method

Refactor World class constructor and destructor. Implement ClearWorld method to delete all objects and reset state.

* Add RaceManager to World class

* Update ValidateString for editor mode checks

Refactor ValidateString to handle editor mode and empty strings.

* Update Text.cpp

* Add SetText method to Text class

* Document RunGarbageCollector function

Added documentation for the RunGarbageCollector function.

* Refactor Game.cpp by removing dead code

Removed unused ruleset handling and clean-up code.

* Update Game.h

* Remove CM_SpawnFromLevelProps call

* Update Text.cpp

* Update World.cpp

* Add Clean method to RaceManager class

* Update RaceManager.cpp

* Update World.cpp

* Update World.h

* Update World.cpp

src/engine/GarbageCollector.cpp

@@ -1,6 +1,9 @@
 #include "GarbageCollector.h"
 #include "World.h"
 
+/**
+ * Removes objects if they are marked for deletion
+ */
 void RunGarbageCollector() {
     CleanActors();
     CleanObjects();