Fixes to horizontal menu logic. Now supports multiple levels of menu items. Added FontIcon component to reduce duplicate code.

Oqtane.Client/Themes/Controls/FontIcon.razor.cs

@@ -0,0 +1,10 @@
+using Microsoft.AspNetCore.Components;
+
+namespace Oqtane.Themes.Controls
+{
+    public partial class FontIcon : ComponentBase
+    {
+        [Parameter()]
+        public string Value { get; set; }
+    }
+}