Input improvements and Text Settings cleanup

[Jowan-Spooner]

• should replace #2183

Thanks so much to @StrangeLost to bringing this to my attention and providing a MRP!

• uses is_action_JUST_pressed for input handling, avoiding issues where by having the mouse pressed and moving while advancing, you could trigger advance twice.
• move skip delay blocking to the beginning of text events
• expose "Advance Delay"
• cleanup text settings scene/script