This is how we do it for confirmation with suggestions too, so be consistent. It
will make things easier later in this branch if we only have one context per
"panel" on the stack, even if the panel consists of two views.
Concretely this means:
- only push the message context onto the stack when opening the panel (this
requires making the description view visible manually; we do the same for
suggestions)
- when switching between message and description, use ReplaceContext rather than
PushContext
22dc7fece9