Make invalid callback in call queue error more verbose

[theraot]

Describe the project you are working on

A 3D platformer with some hybrid mechanics

Describe the problem or limitation you are having in your project

After some refactoring I started getting errors like this:

Trying to execute a deferred call/notification/set on a previously freed instance. Consider using queue_free() instead of free()."

Which didn't lead me to the source of the problem.

Describe the feature / enhancement and how it helps to overcome the problem or limitation

We can distinguish call, notification, and set cases. Furthermore, for call and set we might include the name of the member in the error text, or we can include the notification numerical value.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

We check using switch (message->type & FLAG_MASK) which case it is. And we use message->callable.get_method() to get the members, or message->notification for the notification.

If this enhancement will not be used often, can it be worked around with a few lines of script?

Can't be done with a script.

Is there a reason why this should be core and not an add-on in the asset library?

Can't be done with a script.

[KoBeWi]

Note that godotengine/godot#78987, which introduced this error, is likely going to be reverted (see godotengine/godot#78987 (comment)).

[YuriSizov]

See godotengine/godot#80024 (comment).