✏️ Replace logos and add favicon

- Replaced logo assets and added favicon.ico.

Author: ajaysskumar

TestArena/Layout/HeaderComponent.razor

@@ -7,7 +7,7 @@
                 <!-- Logo on the left -->
                 <div class="col-12 col-md-4 d-flex justify-content-md-start justify-content-center">
                     <a class="btn text-white d-flex align-items-center" href="/">
-                        <img src="/images/shared/logo.png" alt="Logo" class="me-2 mg-fluid rounded" style="height: 2rem;">
+                        <img src="/images/shared/logo.png" alt="Logo" class="me-2 mg-fluid rounded" style="height: 3rem;">
                         <h3 class="m-0">Dev Codex</h3>
                     </a>
                 </div>

TestArena/logo.svg

@@ -31,7 +31,7 @@
     <link href="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/themes/prism.min.css" rel="stylesheet" />
     <script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/prism.min.js" defer></script>
     <script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.29.0/components/prism-csharp.min.js" defer></script>
-<link rel="icon" type="image/png" href="favicon.png" />
+<link rel="icon" type="image/x-icon" href="favicon.ico" sizes="72x72" />
 <link href="TestArena.styles.css" rel="stylesheet" />
 </head>