Update issue state badge and buttons after slash command

When I use a slash command on an issue to Close it or Reopen it, neither the badge with the state or the buttons show the new state:

We could update the buttons, both the ones on the top and the ones on the bottom and the badge when a slash command is used to Close or Reopen an issue.

@victorwu What do you think? (Could not find any issue for this, yet)

cc @smcgivern as I think this falls under Discussion and @DouweM as I was discussing this with you :)

mentioned in merge request !12069 (merged)

I think dupe of https://gitlab.com/gitlab-org/gitlab-ce/issues/29978. If yes, let's close one of them.

It's not an exact duplicate, but I think solving that would solve this

closed

mentioned in issue #29978 (moved)