Implemented download service

Moonlight.Client/Services/DownloadService.cs

@@ -0,0 +1,34 @@
+using System.Text;
+using Microsoft.JSInterop;
+
+namespace Moonlight.Client.Services;
+
+public class DownloadService
+{
+    private readonly IJSRuntime JsRuntime;
+    
+    public DownloadService(IJSRuntime jsRuntime)
+    {
+        JsRuntime = jsRuntime;
+    }
+
+    public async Task DownloadStream(string fileName, Stream stream)
+    {
+        using var streamRef = new DotNetStreamReference(stream);
+
+        await JsRuntime.InvokeVoidAsync("moonlight.utils.download", fileName, streamRef);
+    }
+
+    public async Task DownloadBytes(string fileName, byte[] bytes)
+    {
+        var ms = new MemoryStream(bytes);
+        
+        await DownloadStream(fileName, ms);
+        
+        ms.Close();
+        await ms.DisposeAsync();
+    }
+
+    public async Task DownloadString(string fileName, string content) =>
+        await DownloadBytes(fileName, Encoding.UTF8.GetBytes(content));
+}