Big refactor: Fix plugin issues when disabling/reenabling plugins (#598)

Co-authored-by: balloonpopper <5151242+balloonpopper@users.noreply.github.com>
Co-authored-by: Duncan Brown <duncan@prometheussoftware.ca>

addons/escoria-core/ui_library/menus/options/options.gd

@@ -24,6 +24,7 @@ func _ready() -> void:
 			$VBoxContainer/MarginContainer/options/flags
 	for child in _flags_container.get_children():
 		_flags_container.remove_child(child)
+		child.queue_free()
 
 	_loaded_languages = []
 
@@ -38,7 +39,6 @@ func _ready() -> void:
 			_flags_container.add_child(_lang)
 			_lang.connect("gui_input", self, "_on_language_input", [lang])
 
-
 # Show the options
 func show():
 	backup_settings = escoria.settings.duplicate()