Add ZoomSpeed parameter to ImagePreviewer component

Enhance the `ImagePreviewer` in `ImageViewer.razor` by introducing a new `ZoomSpeed` parameter, allowing users to adjust the zoom speed when displaying images. This update also includes the addition of the `ZoomSpeed` property in `ImageViewer.razor.cs`, making it publicly accessible and documented for better usability.

Author: h2ls

src/BootstrapBlazor/Components/ImageViewer/ImageViewer.razor

@@ -14,7 +14,7 @@
 
     @if (ShowPreviewList)
     {
-        <ImagePreviewer Id="@PreviewerId" ZIndex="@ZIndex" PreviewList="PreviewList" />
+        <ImagePreviewer Id="@PreviewerId" ZIndex="@ZIndex" ZoomSpeed="@ZoomSpeed" PreviewList="PreviewList" />
     }
 </div>
 

src/BootstrapBlazor/Components/ImageViewer/ImageViewer.razor.cs

@@ -118,6 +118,12 @@ public partial class ImageViewer
     [Parameter]
     public bool IsIntersectionObserver { get; set; }
 
+    /// <summary>
+    /// 获得/设置 预览缩放速度
+    /// </summary>
+    [Parameter]
+    public double ZoomSpeed { get; set; }
+
     [Inject]
     [NotNull]
     private IIconTheme? IconTheme { get; set; }