feat(ui-test): 增加测试页面用于测试 UI，仅 Debug 模式编译 - #3505

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Nullability of type of parameter 'message' doesn't match overridden member (possibly because of nullability attributes).

Nullability of type of parameter 'message' doesn't match overridden member (possibly because of nullability attributes).

Calling 'ArgumentNullException.ThrowIfNull' and passing a non-nullable value is a no-op (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca2264)

Calling 'ArgumentNullException.ThrowIfNull' and passing a non-nullable value is a no-op (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca2264)