Overall code re-organizing & layer renaming changes

- When renaming a layer, the line edit grabs the focus. If enter is pressed, it gets invisible. Also fixed positioning and size
- Re-organized the variables in Global, now they are less messy and randomly placed
- Layer, frame & brush textures stretch mode has been changed to Keep Aspect Centered

Scripts/Guides.gd

@@ -13,7 +13,7 @@ func _ready() -> void:
 	width = 0.1
 
 # warning-ignore:unused_argument
-func _process(delta) -> void:
+func _process(delta : float) -> void:
 	width = Global.camera.zoom.x
 	mouse_pos = get_local_mouse_position()
 	var point0 := points[0]