feat: implement 16 ListView CRUD events (FritzAndFriends#356)

Add missing Web Forms-parity properties to ListView EventArgs types:

- ListViewInsertEventArgs: add Values (IOrderedDictionary)
- ListViewUpdateEventArgs: add Keys, OldValues, NewValues (IOrderedDictionary)
- ListViewDeleteEventArgs: add Keys, Values (IOrderedDictionary)
- ListViewPagePropertiesChangingEventArgs: add TotalRowCount

All 16 events were already wired with [Parameter] EventCallbacks and
HandleCommand routing. This commit completes EventArgs property parity
with System.Web.UI.WebControls originals.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: csharpfritz

src/BlazorWebFormsComponents/ListViewDeleteEventArgs.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Specialized;
 
 namespace BlazorWebFormsComponents
 {
@@ -10,6 +11,8 @@ public class ListViewDeleteEventArgs : EventArgs
 		public ListViewDeleteEventArgs(int itemIndex)
 		{
 			ItemIndex = itemIndex;
+			Keys = new OrderedDictionary();
+			Values = new OrderedDictionary();
 		}
 
 		/// <summary>
@@ -21,5 +24,15 @@ public ListViewDeleteEventArgs(int itemIndex)
 		/// Gets or sets a value indicating whether the event should be cancelled.
 		/// </summary>
 		public bool Cancel { get; set; }
+
+		/// <summary>
+		/// Gets a dictionary of field name/value pairs that represent the key of the item to delete.
+		/// </summary>
+		public IOrderedDictionary Keys { get; }
+
+		/// <summary>
+		/// Gets a dictionary of the non-key field name/value pairs in the item to delete.
+		/// </summary>
+		public IOrderedDictionary Values { get; }
 	}
 }

src/BlazorWebFormsComponents/ListViewInsertEventArgs.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Specialized;
 
 namespace BlazorWebFormsComponents
 {
@@ -9,6 +10,7 @@ public class ListViewInsertEventArgs : EventArgs
 	{
 		public ListViewInsertEventArgs()
 		{
+			Values = new OrderedDictionary();
 		}
 
 		/// <summary>
@@ -20,5 +22,10 @@ public ListViewInsertEventArgs()
 		/// Gets the item to be inserted.
 		/// </summary>
 		public object Item { get; set; }
+
+		/// <summary>
+		/// Gets the values for the record to insert.
+		/// </summary>
+		public IOrderedDictionary Values { get; }
 	}
 }

src/BlazorWebFormsComponents/ListViewPagePropertiesChangingEventArgs.cs

@@ -22,5 +22,10 @@ public ListViewPagePropertiesChangingEventArgs(int startRowIndex, int maximumRow
 		/// Gets the maximum number of items to display on each page.
 		/// </summary>
 		public int MaximumRows { get; }
+
+		/// <summary>
+		/// Gets or sets the total number of rows in the underlying data source.
+		/// </summary>
+		public int TotalRowCount { get; set; }
 	}
 }

src/BlazorWebFormsComponents/ListViewUpdateEventArgs.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Specialized;
 
 namespace BlazorWebFormsComponents
 {
@@ -10,6 +11,9 @@ public class ListViewUpdateEventArgs : EventArgs
 		public ListViewUpdateEventArgs(int itemIndex)
 		{
 			ItemIndex = itemIndex;
+			Keys = new OrderedDictionary();
+			OldValues = new OrderedDictionary();
+			NewValues = new OrderedDictionary();
 		}
 
 		/// <summary>
@@ -21,5 +25,20 @@ public ListViewUpdateEventArgs(int itemIndex)
 		/// Gets or sets a value indicating whether the event should be cancelled.
 		/// </summary>
 		public bool Cancel { get; set; }
+
+		/// <summary>
+		/// Gets a dictionary of field name/value pairs that represent the key of the item to update.
+		/// </summary>
+		public IOrderedDictionary Keys { get; }
+
+		/// <summary>
+		/// Gets a dictionary that contains the original values of the item to update.
+		/// </summary>
+		public IOrderedDictionary OldValues { get; }
+
+		/// <summary>
+		/// Gets a dictionary that contains the revised values of the item to update.
+		/// </summary>
+		public IOrderedDictionary NewValues { get; }
 	}
 }