Migrated HttpQueryStringModelBinder into netcore.

src/Umbraco.Web.Common/ModelBinders/HttpQueryStringModelBinder.cs

@@ -0,0 +1,51 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc.ModelBinding;
+using Microsoft.Extensions.Primitives;
+using Umbraco.Core;
+using Umbraco.Web.Common.Extensions;
+
+namespace Umbraco.Web.Common.ModelBinders
+{
+    /// <summary>
+    /// Allows an Action to execute with an arbitrary number of QueryStrings
+    /// </summary>
+    /// <remarks>
+    /// Just like you can POST an arbitrary number of parameters to an Action, you can't GET an arbitrary number
+    /// but this will allow you to do it.
+    /// </remarks>
+    public sealed class HttpQueryStringModelBinder : IModelBinder
+    {
+        public Task BindModelAsync(ModelBindingContext bindingContext)
+        {
+            var queryStrings = GetQueryAsDictionary(bindingContext.ActionContext.HttpContext.Request.Query);
+            var queryStringKeys = queryStrings.Select(kvp => kvp.Key).ToArray();
+            if (queryStringKeys.InvariantContains("culture") == false)
+            {
+                queryStrings.Add("culture", new StringValues(bindingContext.ActionContext.HttpContext.Request.ClientCulture()));
+            }
+
+            var formData = new FormCollection(queryStrings);
+            bindingContext.Result = ModelBindingResult.Success(formData);
+            return Task.CompletedTask;
+        }
+
+        private Dictionary<string, StringValues> GetQueryAsDictionary(IQueryCollection query)
+        {
+            var result = new Dictionary<string, StringValues>();
+            if (query == null)
+            {
+                return result;
+            }
+
+            foreach (var item in query)
+            {
+                result.Add(item.Key, item.Value);
+            }
+
+            return result;
+        }
+    }
+}