## Issue
6542 Livestream listing and blocked list kills CLS score
This is basically a repeat of what was done on `claimTileDiscover` (homepage), but now on `claimListDiscover` (category pages).
This handles the unnecessary re-render when:
- the uri list temporarily being zero while waiting for new claim-search results.
- livestream claim-search invalidating the list.
## Changes
Store the last uri list and use that when we know that claim-search is still not done.
## Tests
1. Ran Lighthouse on category pages (force a livestream channel on it). CLS score must be green.
2. Block `claim_search` from Dev Tools and move to another category. The page should say "timed out" instead of "no results" (i.e. maintain existing behavior).
50c606d916