Added feature for clearing a single field, when clicking on it

Author: szv

src/CodeBreaker.Blazor.Client/Components/Playground.razor.cs

@@ -117,10 +117,19 @@ private void ResetMove() =>
     private void SelectField(int index)
     {
         _selectedField = index;
-        
+
+        // Set all fields to not selected
         for (int i = 0; i < _currentMove.Length; i++)
             _currentMove[i].Selected = false;
-        
+
+        // Reset the field, if it is already filled
+        if (_currentMove[_selectedField].Color is not null || _currentMove[_selectedField].Shape is not null)
+        {
+            _currentMove[_selectedField].Color = null;
+            _currentMove[_selectedField].Shape = null;
+        }
+
+        // Set the selected field to selected
         _currentMove[_selectedField].Selected = true;
         _selectable = true;
     }