Work items show icons and actions when item is not found
Summary
When a work item is not found we show a not found screen, however some elements are still presented as if the item existed.
Specifically users see a type icon and the actions menu with the ability to subscribe to the item or copy reference.
Additionally the "not found" view is not centered within the body.
Steps to reproduce
Access a work items route using a nonexistent ID such as https://gitlab.com/gitlab-org/plan-stage/okr-sandbox/-/work_items/99999
Example Project
gitlab
What is the current bug behavior?
The work item type icon and actions are shown, and the message is not centered.
What is the expected correct behavior?
No content appears other than the "not found" error, centered in the body.
Relevant logs and/or screenshots
Output of checks
Results of GitLab environment info
Expand for output related to GitLab environment info
(For installations with omnibus-gitlab package run and paste the output of: `sudo gitlab-rake gitlab:env:info`) (For installations from source run and paste the output of: `sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)
Results of GitLab application Check
Expand for output related to the GitLab application check
(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true
)(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true
)(we will only investigate if the tests are passing)