Remove virtuality from MemoryItem

source/RobotAPI/libraries/armem/core/base/CoreSegmentBase.h

source/RobotAPI/libraries/armem/core/base/EntityBase.h

...e/RobotAPI/libraries/armem/core/base/EntityInstanceBase.h

...e/RobotAPI/libraries/armem/core/base/EntitySnapshotBase.h

source/RobotAPI/libraries/armem/core/base/MemoryBase.h

.../RobotAPI/libraries/armem/core/base/ProviderSegmentBase.h

...PI/libraries/armem/core/base/detail/MemoryContainerBase.h

...ce/RobotAPI/libraries/armem/core/base/detail/MemoryItem.h

source/RobotAPI/libraries/armem/test/ArMemMemoryTest.cpp

source/RobotAPI/libraries/armem_gui/memory/TreeWidget.cpp

source/RobotAPI/libraries/armem_gui/memory/TreeWidget.h