Conditional decorations based on message/type/source

[barthbv]

Hello !

Not really an issue, but I was wondering if there is any way or if there are any plans for having conditional decorations for specific errors/message, since I saw in the docs that you can replace an error message with a custom one.

Use case would be for example, unused code in Dart is treated as a warning, but could be restyled like in Android Studio where it is just greyed out.

That's the only use case I can think of really ! (Edit : TODOs actually, might be another good one)
I always felt like unused code should be on its own diagnostic category, but I'm a noob, so feel free to yell at me about how wrong I am.

Thank you for an awesome extension btw, I tend to rely a lot on colors and styling to navigate my code and stuff like highlighting the whole line instead of the default squiggly underlines made everything so much more readable for me.