Create a search field for labels

Description

It's annoying when we need to edit a label, there's no search bar or filter. We need to guess which page the label is on to be able to find it. Example: https://gitlab.com/gitlab-com/www-gitlab-com/labels - try to find backend there.

Proposal

Create a search bar for the labels page.

Documentation blurb

If accepted, we'll need to update:

• https://docs.gitlab.com/ee/user/project/labels.html#labels
• https://docs.gitlab.com/ee/user/search/index.html#search-through-gitlab

cc/ @tauriedavis @victorwu

#27031 (moved) Add 'Filter by name' to the Milestones and Labels page
#29343 (moved) Add ability filter labels

Totally agree here but closing as duplicate

closed