Not clear which non-widget data types get expanded and which don't


In this example, `Theme` has a `ThemeData`. It's not clear to me whether there's just a whitelisted handpicked set of "data" types that expands into its constituents and why `ThemeData` is opaque but `TextStyle` under `actionTextStyle` is expandable.

Also a bit inconsistent that `Theme` has an opaque `ThemeData` (which follows the real tree composition) but the `CupertinoTheme`'s `CupertinoThemeData` is somehow inlined into the `CupertinoTheme` node directly. Same with the `IconTheme` where the `IconThemeData` is inlined.

首先定位决定如何展开对象节点和数据节点的 widget inspector 代码。将 ThemeData、TextStyle、CupertinoThemeData 和 IconThemeData 的处理方式与 issue 中所示的行为进行比较。完成后应能明确展开规则，并解释或解决处理不一致的问题。

由索引模型根据 Issue 内容生成。