added return value to skill execute method

...API/components/armem/server/SkillsMemory/SkillsMemory.cpp

...otAPI/components/armem/server/SkillsMemory/SkillsMemory.h

source/RobotAPI/interface/skills/SkillManagerInterface.ice

source/RobotAPI/interface/skills/SkillProviderInterface.ice

.../libraries/skills/manager/SkillManagerComponentPlugin.cpp

...PI/libraries/skills/manager/SkillManagerComponentPlugin.h

source/RobotAPI/libraries/skills/provider/Skill.cpp

source/RobotAPI/libraries/skills/provider/Skill.h

...ibraries/skills/provider/SkillProviderComponentPlugin.cpp

.../libraries/skills/provider/SkillProviderComponentPlugin.h

...ies/skills/provider/detail/SkillImplementationWrapper.cpp

...aries/skills/provider/detail/SkillImplementationWrapper.h