Usage of IDisposable & Free() in C#

Godot 3.2.2

I've been searching/asking for a definitive answer to this question both in the [QA section](https://godotengine.org/qa/79183/idisposable-%26-free-in-c%23), [Reddit](https://www.reddit.com/r/godot/comments/ibaq0d/idisposable_free_in_c/) and on Discord, but I have yet been able to find an answer, or even anyone who dares to make a guess.

So, here's a request for documenting the intended usage of the `IDisposable` interface and `Free()`, present in both `Godot.Reference` and `Godot.Object`, and thus all sub classes of these two.

Sub classes of `Godot.Reference` are reference counted, but since the class also implements `IDisposable` it is a fair assumption that `Dispose()`should be called - but this is meant to be a one-time call which does not play well with a reference counted types.

- How are these two memory management systems intended to interact?
- Who is meant to call `Dispose()` and when?
- Who is mean to call `Free()` and when?
- Are we supposed to call both `Free()` and `Dispose()`?
- When does the engine call these methods, i.e. when does ownership of an instance pass to the engine?