Background loading

[univeous]

Is your feature request related to a problem? Please describe.
I've recently considered handing over scene changing in my game to this addon.
However, I realized that it lacks the ability to load scene in background.
without it it's impossible to show the loading screen when loading a large scene.

Describe the solution you'd like
For now I'm using this approach in my own game. I've left out some parts, like the loading screen actually only appears after a certain amount of time has elapsed since loading:

var _target_scene_path :String
var progress := []

func switch_to_scene_path(scene_path: String):
	#...

	await fade_out()
	_target_scene_path = scene_path
	ResourceLoader.load_threaded_request(scene_path, "PackedScene")
	# Show Loading Screen
	LoadingScreen.show()


func _process(_delta: float) -> void:
	if _target_scene_path == "": return
	
	match ResourceLoader.load_threaded_get_status(_target_scene_path, progress):
		ResourceLoader.THREAD_LOAD_LOADED:
			var new_scene = ResourceLoader.load_threaded_get(_target_scene_path)
			
			# Do stuff here to Hide Loading Screen
			LoadingScreen.hide()

			get_tree().change_scene_to_packed(new_scene)
			_target_scene_path = ""
			await fade_in()			
		ResourceLoader.THREAD_LOAD_IN_PROGRESS:
			# Do stuff here to update Loading Screen
			LoadingScreen.update_progress(progress[0])

Describe alternatives you've considered

N/A

Additional context

N/A

[jabsatz]

Hello! As mentioned in the post here #35, I don't think I will be able to add this feature personally. I have tagged the issue however, in case somebody else can pick it up.