fix: WASM ScrollContentPresenter offsets are immediately set after scroll request without animation

Author: MartinZikmund

src/Uno.UI/UI/Xaml/Controls/ScrollContentPresenter/ScrollContentPresenter.wasm.cs

@@ -197,6 +197,16 @@ public void ScrollTo(double? horizontalOffset, double? verticalOffset, bool disa
 
 			if (_pendingScrollTo.HasValue)
 			{
+				if (disableAnimation)
+				{
+					// Ensure offset values match native ones if animation is disabled
+					// as the scroll event may occur only asynchronously
+					// while the values are already set properly.
+					HorizontalOffset = GetNativeHorizontalOffset();
+					VerticalOffset = GetNativeVerticalOffset();
+					ScrollOffsets = new Point(HorizontalOffset, VerticalOffset);
+				}
+
 				// The scroll to was not processed by the native SCP, we need to re-request ScrollTo a bit later.
 				// This happen has soon as the native SCP element is not in a valid state (like un-arranged or hidden).
 
@@ -226,7 +236,7 @@ public void ScrollTo(double? horizontalOffset, double? verticalOffset, bool disa
 							horizontalOffset ?? nativeHorizontalOffset,
 							verticalOffset ?? nativeVerticalOffset,
 							isIntermediate: false
-						); 
+						);
 					}
 				}
 			}