Display nested node configuration warnings

[mieldepoche]

Describe the project you are working on

prototype

Describe the problem or limitation you are having in your project

related to #8252
when you have a hierarchy of nodes, some of the hidden children may have node configuration warnings. There's no way to tell if they're hidden in a folded branch.

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

When a child of a node has a configuration warning, its parents should have a semi-transparent warning.
Clicking it could take you to the problematic node, though there could be several. Idk.

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

folded	unfolded

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

used often

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

small usability improvement on core

[mk56-spn]

this sounds very nice to have for the most part!. If this becomes a thing i would like to request that it be optional. Currently control nodes have what many consider to be a nuisance warning whenever you change their Z order godotengine/godot#69895 and having it be pushed up the tree whenever its parents are collapsed would make the situation even worse.

[Calinou]

I don't see much point in this, since you can't modify a child node's property while it's folded (this is the main situation where a new node configuration warning will appear).

It could be helpful if you inspect another person's project, but at this point I'd prefer something like #5068 which would allow for a project-wide view of all warnings.