Add project restore files and NuGet cache for GsaViewer

- Created project.nuget.cache to store NuGet package cache information.
- Added project.packagespec.json to define project restore settings and dependencies.
- Included rider.project.restore.info for Rider IDE integration.

GsaEditor/Helpers/HexDumper.cs

@@ -0,0 +1,59 @@
+using System.Text;
+
+namespace GsaEditor.Helpers;
+
+/// <summary>
+/// Produces a classic hex + ASCII dump string from a byte array.
+/// </summary>
+public static class HexDumper
+{
+    /// <summary>
+    /// Formats a byte array as a hex dump with offset, hex values, and printable ASCII characters.
+    /// </summary>
+    /// <param name="data">The data to dump.</param>
+    /// <param name="maxBytes">Maximum number of bytes to include in the dump.</param>
+    /// <returns>A formatted hex dump string.</returns>
+    public static string Dump(byte[] data, int maxBytes = 512)
+    {
+        var sb = new StringBuilder();
+        int length = Math.Min(data.Length, maxBytes);
+        const int bytesPerLine = 16;
+
+        for (int offset = 0; offset < length; offset += bytesPerLine)
+        {
+            // Offset column
+            sb.Append($"{offset:X8}  ");
+
+            int lineLen = Math.Min(bytesPerLine, length - offset);
+
+            // Hex columns
+            for (int i = 0; i < bytesPerLine; i++)
+            {
+                if (i < lineLen)
+                    sb.Append($"{data[offset + i]:X2} ");
+                else
+                    sb.Append("   ");
+
+                if (i == 7) sb.Append(' ');
+            }
+
+            sb.Append(' ');
+
+            // ASCII column
+            for (int i = 0; i < lineLen; i++)
+            {
+                byte b = data[offset + i];
+                sb.Append(b >= 0x20 && b < 0x7F ? (char)b : '.');
+            }
+
+            sb.AppendLine();
+        }
+
+        if (data.Length > maxBytes)
+        {
+            sb.AppendLine($"... ({data.Length - maxBytes} more bytes)");
+        }
+
+        return sb.ToString();
+    }
+}