JWT Query Parameter Auth for IPTV Links (#1215)

* JWT Auth

* Standardized url variable additions

* formatting and minor refactoring

* this isn't needed

* allow channel logos without auth

* update changelog

---------

Co-authored-by: Ministorm3 <4474921+Ministorm3@users.noreply.github.com>

ErsatzTV/JwtHelper.cs

@@ -0,0 +1,20 @@
+using Microsoft.IdentityModel.Tokens;
+using System.Text;
+
+namespace ErsatzTV;
+
+public static class JwtHelper
+{
+    public static void Init(IConfiguration configuration)
+    {
+        string issuerSigningKey = configuration["JWT:IssuerSigningKey"];
+        IsEnabled = !string.IsNullOrWhiteSpace(issuerSigningKey);
+        if (IsEnabled)
+        {
+            IssuerSigningKey = new SymmetricSecurityKey(Encoding.ASCII.GetBytes(issuerSigningKey!));
+        }
+    }
+
+    public static SymmetricSecurityKey IssuerSigningKey { get; private set; }
+    public static bool IsEnabled { get; private set; }
+}