[NUI][AT-SPI] Detach NUIViewAccessible in View.Dispose()

The application may crash if the View is disposed but the Accessibility
infrastructure calls one of the View methods. Detaching the
NUIViewAccessible proxy object in View.Dispose() should prevent that.

src/Tizen.NUI/src/internal/Interop/Interop.ControlDevel.cs

@@ -539,6 +539,9 @@ private AccessibilityDelegate()
 
             [DllImport(NDalicPINVOKE.Lib, EntryPoint = "CSharp_Dali_Accessibility_SetAccessibilityDelegate")]
             public static extern IntPtr DaliAccessibilitySetAccessibilityDelegate(IntPtr arg1_accessibilityDelegate, uint arg2_accessibilityDelegateSize);
+
+            [DllImport(NDalicPINVOKE.Lib, EntryPoint = "CSharp_Dali_Accessibility_DetachAccessibleObject")]
+            public static extern void DaliAccessibilityDetachAccessibleObject(HandleRef arg1_control);
         }
     }
 }

src/Tizen.NUI/src/public/BaseComponents/ViewAccessibility.cs

@@ -397,6 +397,9 @@ protected override void Dispose(bool disposing)
 
             internalName = null;
 
+            Interop.ControlDevel.DaliAccessibilityDetachAccessibleObject(SwigCPtr);
+            if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
+
             if (disposing == false)
             {
                 if (IsNativeHandleInvalid() || SwigCMemOwn == false)

src/Tizen.NUI/src/public/BaseComponents/ViewAccessibilityWrappers.cs

@@ -113,8 +113,6 @@ private static void InitializeAccessibilityDelegateAccessibleInterface()
         private static ulong AccessibilityCalculateStatesWrapper(IntPtr self, ulong initialStates)
         {
             View view = GetViewFromRefObject(self);
-            if (view == null)
-                return 0UL;
 
             ulong bitMask = 0UL;