Added NC softkeys:

- API config
- SignalR thread
- SignalR click handler

Step.Model/ConfigModels/UserSoftKeyConfigModel.cs

@@ -0,0 +1,24 @@
+using System.Collections.Generic;
+using static Step.Model.Constants;
+
+namespace Step.Model.ConfigModels
+{
+    public class UserSoftKeyConfigModel
+    {
+        public int Id { get; set; }
+        public Dictionary<string, string> LocalizedNames { get; set; }
+        public int Category { get; set; }
+        public bool IsActive { get; set; }
+        public bool OperatorConfirmationNeeded { get; set; }
+        public List<SubKeysModel> SubKeys { get; set; }
+        public int PlcId { get; set; }
+        public SOFTKEY_TYPE Type { get; set; }
+    }
+
+    public class SubKeysModel
+    {
+        public int Id;
+        public int PlcId;
+        public string Text;
+    }
+}