Feature request to organise Friends and Direct Messages lists

I have a fairly substantial list of people who I communicate with personally on a one-to-one basis, alongside the numerous servers I frequent. However, the current friend list, and particualrly the active Direct Messages list, offer nothing to help organise people.

I've ended up weakening friendships because I don't see them more clearly, getting lost in the fuzz of names of other people I'm talking to. Being able to assign friends a tag that groups those DMs together would make keeping track of those I want to continue with much easier, and in particular help me keep track of exactly what I talk to them about, whether it's a particular game, hobby or topic.