[Feature Request] Include hierarchy

[gikari]

Some IDEs have "include hierarchy" functionality: you can view what headers are included in the current file and in which files the current header is included using a tree view.

For example, Qt Creator:
https://doc.qt.io/qtcreator/creator-include-hierarchy-view.html

CLion (import hierarchy):
https://www.jetbrains.com/help/clion/analyzing-applications.html

Displaying a tree of includes will be a useful feature.