search: update index status page
Created by: stefanhengl
This is a purely cosmetic refactor. Some data, such as "files" and "shards", were in parenthesis but deserve their own row. We also update the pluralization for the unindexed files.
Test plan
- manual testing: I ran a local instance and inspected the page for several repos.
App preview:
Check out the client app preview documentation to learn more.