[API] need public property which return m_SelectedSlot in ItemViewSlotsContainerBase.cs


To track the "current selected" slot exactly, we have to monitoring many events
ClientInventoryGrid.OnItemViewSlotSelected += OnClientSlotSelected;
ClientInventoryGrid.OnItemViewSlotDeselected += OnClientSlotDeselected;
StorageInventoryGrid.OnItemViewSlotSelected += OnStorageSlotSelected;
StorageInventoryGrid.OnItemViewSlotDeselected += OnStorageSlotDeselected;

But in fact, we already has
m_SelectedSlot and m_ItemViewSlots in container
Could you please help to add public perperty whose getter return these two memeber?
so that we could do similar thing via
var cur_slot = ClientInventoryGrid.SelectedSlot;
just like what we did for
public IReadOnlyList<ItemViewSlot> ItemViewSlots => m_ItemViewSlots;