Universal Outline2D Shader (with fix for Godot 4.x)

[Dreadset]

Created a universal Outline2D shader script and fixed error regarding uniform 'hint_color' (it's called 'source_color' since Godot 4.0).

This script is a refactored combination of the shaders "outline2D_inner", "outline2D_outer" and "outline2D_inner_outer". With this, you can easily choose the desired outline in the inspector. Also added the possibility to turn the outline on and off via the inspector.