StyleEditor: Make value input fields save changes instantly

[Proggle]

In the Godot main editor, every time a value is changed in a text box it is instantly active. However, in dialogic this does not appear to be the case; if you edit a value in the style editor but leave your cursor in the box, it does not update, so if you're trying to do rapid iteration on the look of your dialog boxes (and using godot's scene runner instead of dialogic's style preview) it looks like nothing has changed, and then things suddenly change abruptly when you move onto the next value to alter.

This was quite confusing for me, and checking the discord there are a lot of people who keep asking 'why doesn't this value change' followed by 'nvm for some reason it's working now'.