Make icon as simple additional string

[niciki-niciki]

Hi, I need to say: I love this extension!

Can you make a change to use "icon" as simple, additional string? That way we could use all emojis that exists already!

Please look at my result with vivado.log:

To do so, I used icon as "none" and put proper emojis in prefix, based on different regexp matching. That would be cool to put it in icon instead of prefix. That way I could fill already empty place for icon in a CodeMap list.

Best regards, Daniel