Added bracket support

Commands/CalculateCommand.cs

@@ -1,38 +0,0 @@
-using calculator.Common;
-using calculator.Model;
-using calculator.Services;
-
-namespace calculator.Commands;
-
-public class CalculateCommand : ICommand
-{
-    private readonly ICaculator _caculator;
-    private readonly CaculatorData _data;
-    private readonly double? _b;
-    private readonly Operation _operation;
-    private double? _previousValue;
-
-    public CalculateCommand(ICaculator caculator, CaculatorData data)
-    {
-        _caculator = caculator;
-        _data = data;
-        _operation = data.Operation.Value;
-        
-        if (double.TryParse(data.Input, out var b)) 
-            _b = b;
-    }
-
-    public void Execute()
-    {
-        if (_data.Value is null)
-            return;
-        _previousValue = _data.Value;
-        _data.Value = _caculator.Calculate(_operation, _data.Value.Value, _b);
-        _data.Input = null;
-    }
-
-    public void Undo()
-    {
-        _data.Value = _previousValue;
-    }
-}