Please add properties to WPF for traversing Parent/Children nodes

I'm trying to write a converter to convert a [text selection](https://learn.microsoft.com/en-us/dotnet/api/system.windows.documents.textrange) from [`FlowDocument`](https://learn.microsoft.com/en-us/dotnet/api/system.windows.documents.flowdocument) to some other text format.

# Current Situation

Currently, this is impossbile as all the navigating methods and properties are internal to the WPF framework.

The only workaround is to serialize the selected nodes to XAML using a [`XamlWriter`](https://learn.microsoft.com/en-us/dotnet/api/system.windows.markup.xamlwriter) and using an [`XmlReader`](https://learn.microsoft.com/en-us/dotnet/api/system.xml.xmlreader) or similar to traverse the generated XML.

The current solution is very cumbersome, slow, memory intensive and unnecessary.

# Desired Situation

Please add `Parent` and `Children` properties to the [`DependencyObject`](https://learn.microsoft.com/en-us/dotnet/api/system.windows.dependencyobject) class, so we can traverse through any WPF object tree.