Draft: imprv: Show all errors in chat view

Errors "rows" disappear when you switch contacts, but I think it is useful to display nonetheless? I have been running with this for a week and it did not pollute conversation views (I was concerned we might get too many of those from MUCs, it does not seem to be the case).

EDIT: well, I just had this in a 1:1 chat

Not really an issue, and probably related to delivery receipts or displayed markers, but this is probably not something we want to show by default.