PM UI issue

I noticed this while sending out lots of PMs for my game giveaway thread. It's not a huge issue at all and doesn't really have any meaningful effect on the site's usability, but I thought I would mention it anyway.

Also, it might already be in the Gitlab, but I looked around and didn't see anything. I don't have an account there, so could someone (maybe @cfabbro?) add it for me if needed?

Issue: Within a PM conversation, there is no indication of the person who is being PMed unless they have responded.

Steps to recreate: send a user a PM, then click on that message from sent messages. If the person has not responded, you will only see your username and message. If the person responds, you can then see their username on their response, but that's currently the only way to know who the conversation is with from within the conversation itself.

If anyone wants to recreate this for themselves, feel free to send me a PM referencing this thread and I will not respond.