CommandBar NRE on PrimaryCommands.Add

[workgroupengineering]

Describe the bug
Throwed NRE add PrimaryCommands.Add.

Steps

1. Add following xaml at your view

         <ui:CommandBar x:Name="MyBar"
                   HorizontalAlignment="Right"
                   Grid.Column="4"/>

2. On code-behind add code like this:

       void Button_Click(object sender, EventArgs e)
       {
           MyBar.PrimaryCommands.Add(new CommandBarButton(){ Label="Test"});
       }

3. On Click button NRE is throw

Screenshots
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Desktop/Platform (please complete the following information):

• OS: All
• FluentAvalonia Version [e.g. 1.0.0, or latest]: 2.0.5
• Avalonia Version: 11.0.6

Additional context
Add any other context about the problem here.

[workgroupengineering]

Workaround

<ui:CommandBar x:Name="MyBar"
                HorizontalAlignment="Right"
                Grid.Column="4">
        <ui:CommandBar.PrimaryCommands>
          <ui:CommandBarButton/>
        </ui:CommandBar.PrimaryCommands>
        <ui:CommandBar.SecondaryCommands>
          <ui:CommandBarButton/>
        </ui:CommandBar.SecondaryCommands>
</ui:CommandBar>