Make the button show that the ticket has been resolved

It's a bit weird having a "mark as resolved" button on resolved tickets:

idk if it's possible to edit the button properties, but if we can, we should probably disable it and change the text

Start by locating the implementation of the “mark as resolved” button and the view for already-resolved tickets. Confirm how the button state and label are set, then verify that resolved tickets show a disabled button with wording that indicates the ticket is already resolved.

Written by the indexing model from the issue text.