Obey "Draw Relationship Lines" setting

[YeldhamDev]

Could make the tree obey the "Draw Relationship Lines" setting? It also hides the lines drawn in-between the items.

[Zylann]

I'm trying to do this:

	EditorSettings.connect("settings_changed", self, "_on_EditorSettings_settings_changed")

But Godot throws an error:

ERROR: In Object of type 'GDScriptNativeClass': Attempt to connect nonexistent signal 'settings_changed' to method 'EditorPlugin._on_EditorSettings_settings_changed'
   At: core/object.cpp:1404

In fact, EditorSettings.get_setting also doesn't work, not sure how I am supposed to access this singleton...
I'll try with EditorInterface, it's weird that singletons in C++ don't map those you have in GDScript

[Zylann]

231a74c
I managed to make it work with the same code as the scene tree, but it still doesn't hide the lines between the items for some reason.
It also doesn't in the normal scene tree ¯\(ツ)/¯ (in 3.0.6)

[YeldhamDev]

The new changes work completely fine in 3.1, so I'm closing the issue.

Thanks!