Find Inheritors of a Script in the Editor and in Code

[Gonderage]

I would like to get all the inheritors of a script, whether they're given classnames or not, in the filesystem, both through code (probably through EditorInterface?) and through a GUI like how View Owners works. Currently, to accomplish this, I use a script to browse the project filesystem and load gdscripts to check what they inherit.
An example use case is a problem I have right now: I need to get the display name from every scene that has an instance of a base object script so I can put the display names in a POT file for translation. But the scenes that use an inheriting script are inconsistently scattered across the project. To find those instances, I would first use View Owners (which I have another issue with it being a GUI-only feature), but that doesn't show me anything at all. This happens because, in my team's project, each base object scene uses its own script inheriting from the base object script.