As does the hotkey "i". It's somewhat less appropriate because it's all actions,
but it's where our "info" menu used to be, and we can workshop a better one. "a"
feels weird to me, but maybe it's just me.
You can also hover on the .message_content to see a popover with extra message details
This is for Trac #1334.
(imported from commit f8fbf70c8502370a78159e24f3cf9589fb9d384f)