This PR adds an edit button to the topic timer info message which opens the modal.
Also, I have cleaned up a few more places where we were referencing "topic status update" which is what these were called prior to being called topic timers.
The category settings for auto-close topic hours has now also been modified to use the new relative-time-picker component.
Finally, the relative-time-picker input step and min is dynamic based on mins/other intervals selected, see https://review.discourse.org/t/feature-relative-time-input-for-timers-and-bookmarks-and-promote-auto-close-after-last-post-timer-12063/19204/7?u=martin
* Move new/edit category modals to its own page
* Fix JS tests
* Minor fixes to new-category UI
* Add mobile toggle
* Use global pretender endpoint so plugins can benefit too
* Alignment fix
* Minor review fixes
* Styling refactor
* Move some SCSS out of the modal
