Refine reset logic in Playground class

Introduce a check for `AvailableShapes` to determine if the game uses only colors or both colors and shapes. If `AvailableShapes` is null or empty, reset only the color of the selected field. If both color and shape are set, reset both. Ensure the selected field is marked and `_selectable` is set to true.

Author: szv

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

@@ -122,13 +122,21 @@ private void SelectField(int index)
         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)
+        if (AvailableShapes is null || !AvailableShapes.Any())
         {
+            // Current game only with colors
+            // Reset the color of the selected field (will be selected in the next step)
+            _currentMove[_selectedField].Color = null;
+        }
+        else if (_currentMove[_selectedField].Color is not null && _currentMove[_selectedField].Shape is not null)
+        {
+            // Current game with colors and shapes
+            // Reset the color and shape of the selected field when both are set
             _currentMove[_selectedField].Color = null;
             _currentMove[_selectedField].Shape = null;
         }
 
+
         // Set the selected field to selected
         _currentMove[_selectedField].Selected = true;
         _selectable = true;