Option to always show node names, esp. for Marker2D / Marker3D

[hsandt]

Issue

I added a Marker2D to my scene, but I cannot see its node name as label in the editor until I hover it.

When there are many markers with non-obvious roles, I find them more useful when you can see what they are at a glance.

Proposal

Add an editor setting (maybe in the top-menu Debug) Show Node Names as Labels, Show Marker Names as Labels, or a list of node types to show node names as labels for.

Obviously if there are too close to each other, name labels may be cluttered, so showing all node names may be a bit too much, hence the options to show labels only for nodes of a certain type. But I'm not sure how to show this well in UI, hence this discussion. It's easy for just a few hardcoded types like pure Node2D and Marker2D/3D, but what about supporting all types? Maybe something like Unity's Gizmo setting popup:

And should we enable debug label for all child classes of selected classes, or just that specific class?

Workaround

I suppose _draw functions would be able to draw a custom label containing the name. Then we'd use a custom child class of Marker2D that draws the node name as label near the node position, when a certain project setting flag is true.

That would require to replace all markers (or other node types) with that custom type though.