Added project Mt5Api to VS_2022 solution and disable some code for compilable

MtApi5/Events/OnBookEvent.cs

@@ -2,6 +2,6 @@
 {
     internal class OnBookEvent
     {
-        public string Symbol { get; set; }
+        public string? Symbol { get; set; }
     }
 }

MtApi5/Events/OnLastTimeBarEvent.cs

@@ -2,8 +2,8 @@
 {
     public class OnLastTimeBarEvent
     {
-        public MqlRates Rates { get; set; }
-        public string Instrument { get; set; }
+        public MqlRates? Rates { get; set; }
+        public string? Instrument { get; set; }
         public int ExpertHandle { get; set; }
     }
 }

MtApi5/Events/OnLockTicksEvent.cs

@@ -2,6 +2,6 @@
 {
     internal class OnLockTicksEvent
     {
-        public string Instrument { get; set; }
+        public string? Instrument { get; set; }
     }
 }

MtApi5/Events/OnTickEvent.cs

@@ -2,8 +2,8 @@
 {
     internal class OnTickEvent
     {
-        public MqlTick Tick { get; set; }
-        public string Instrument { get; set; }
+        public MqlTick? Tick { get; set; }
+        public string? Instrument { get; set; }
         public int ExpertHandle { get; set; }
     }
 }

MtApi5/Events/OnTradeTransactionEvent.cs

@@ -2,8 +2,8 @@
 {
     internal class OnTradeTransactionEvent
     {
-        public MqlTradeTransaction Trans { get; set; }
-        public MqlTradeRequest Request { get; set; }
-        public MqlTradeResult Result { get; set; }
+        public MqlTradeTransaction? Trans { get; set; }
+        public MqlTradeRequest? Request { get; set; }
+        public MqlTradeResult? Result { get; set; }
     }
 }