add time zone support for sites and users

Oqtane.Shared/Models/Site.cs

@@ -26,6 +26,11 @@ namespace Oqtane.Models
         /// </summary>
         public string Name { get; set; }
 
+        /// <summary>
+        /// The default time zone for the site
+        /// </summary>
+        public string TimeZoneId { get; set; }
+
         /// <summary>
         /// Reference to a <see cref="File"/> which has the Logo for this site.
         /// Should be an image.
@@ -200,6 +205,7 @@ namespace Oqtane.Models
                 SiteId = SiteId,
                 TenantId = TenantId,
                 Name = Name,
+                TimeZoneId = TimeZoneId,
                 LogoFileId = LogoFileId,
                 FaviconFileId = FaviconFileId,
                 DefaultThemeType = DefaultThemeType,

Oqtane.Shared/Models/TimeZone.cs

@@ -0,0 +1,10 @@
+namespace Oqtane.Models
+{
+    public class TimeZone
+    {
+        public string Id { get; set; }
+
+        public string DisplayName { get; set; }
+
+    }
+}

Oqtane.Shared/Models/User.cs

@@ -29,6 +29,11 @@ namespace Oqtane.Models
         /// </summary>
         public string Email { get; set; }
 
+        /// <summary>
+        /// User time zone
+        /// </summary>
+        public string TimeZoneId { get; set; }
+
         /// <summary>
         /// Reference to a <see cref="File"/> containing the users photo.
         /// </summary>