UX: Increase width & center category reorder input (PR #10928)

Needed to increase selector specificity for padding to work. Also centered alignment.

Discussion here: https://meta.discourse.org/t/2-digit-numbers-not-fully-shown-in-the-categories-reorder-dialog/166933

Screen Shot 2020-10-14 at 10 45 27 PM

GitHub

This pull request has been mentioned on Discourse Meta. There might be relevant details there:

https://meta.discourse.org/t/2-digit-numbers-not-fully-shown-in-the-categories-reorder-dialog/166933/3