Add WorkerLocalData and use it for stats

emper/Emper.hpp

emper/Runtime.cpp

emper/Runtime.hpp

emper/WorkerLocalData.hpp

emper/strategies/AbstractWorkStealingScheduler.cpp

emper/strategies/AbstractWorkStealingScheduler.hpp

emper/strategies/AbstractWorkStealingStats.cpp

emper/strategies/AbstractWorkStealingStats.hpp

emper/strategies/AbstractWorkStealingStrategy.cpp

emper/strategies/AbstractWorkStealingStrategy.hpp

emper/strategies/AbstractWorkStealingWorkerStats.hpp

emper/strategies/laws/LawsDispatcher.cpp

emper/strategies/laws/LawsDispatcher.hpp

emper/strategies/laws/LawsScheduler.cpp

emper/strategies/laws/LawsScheduler.hpp

emper/strategies/laws/LawsStrategy.cpp

emper/strategies/meson.build

emper/strategies/ws/WsScheduler.cpp

emper/strategies/ws/WsScheduler.hpp

emper/strategies/ws/WsStrategy.cpp