Bug: CsWinRT only projects one instance of repeated WinRT attributes

[lgztx96]

Description

CsWinRT does not correctly project multiple instances of the same WinRT attribute from winmd metadata.

When a WinRT type contains multiple instances of the same attribute, CsWinRT only projects one of them. The remaining attribute instances are lost.

Steps To Reproduce

1. Define a WinRT runtime class with multiple TemplateVisualState attributes:

[Microsoft.UI.Xaml.TemplateVisualState("Normal", "CommonStates")]
[Microsoft.UI.Xaml.TemplateVisualState("PointerOver", "CommonStates")]
[Microsoft.UI.Xaml.TemplateVisualState("Pressed", "CommonStates")]
[Microsoft.UI.Xaml.TemplateVisualState("Disabled", "CommonStates")]

[Microsoft.UI.Xaml.TemplateVisualState("Horizontal", "OrientationStates")]
[Microsoft.UI.Xaml.TemplateVisualState("Vertical", "OrientationStates")]

[Microsoft.UI.Xaml.TemplateVisualState("Visible", "ThumbVisibilityStates")]
[Microsoft.UI.Xaml.TemplateVisualState("Collapsed", "ThumbVisibilityStates")]
unsealed runtimeclass SizerBase : Microsoft.UI.Xaml.Controls.Control  
{
    ...
}

2. The generated winmd correctly contains all attributes:

3. CsWinRT-generated C# projection:

Expected Behavior

CsWinRT should preserve all attribute instances from the WinRT metadata when generating the C# projection.

Version Info

Microsoft.Windows.CsWinRT 2.3.1

Additional Context

No response