add time zone support for sites and users

Oqtane.Server/Controllers/TimeZoneController.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Oqtane.Models;
+using Oqtane.Shared;
+
+namespace Oqtane.Controllers
+{
+    [Route(ControllerRoutes.ApiRoute)]
+    public class TimeZoneController : Controller
+    {
+        public TimeZoneController() {}
+
+        // GET: api/<controller>
+        [HttpGet]
+        public IEnumerable<Models.TimeZone> Get()
+        {
+            return TimeZoneInfo.GetSystemTimeZones()
+                .Select(item => new Models.TimeZone
+                {
+                    Id = item.Id,
+                    DisplayName = item.DisplayName
+                })
+                .OrderBy(item => item.DisplayName);
+        }
+    }
+}

Oqtane.Server/Controllers/UserController.cs

@@ -135,6 +135,7 @@ namespace Oqtane.Controllers
                 if (_userPermissions.IsAuthorized(User, user.SiteId, EntityNames.User, -1, PermissionNames.Write, RoleNames.Admin) || _userPermissions.GetUser(User).UserId == user.UserId)
                 {
                     filtered.Email = user.Email;
+                    filtered.TimeZoneId = user.TimeZoneId;
                     filtered.PhotoFileId = user.PhotoFileId;
                     filtered.LastLoginOn = user.LastLoginOn;
                     filtered.LastIPAddress = user.LastIPAddress;