Extracted `fetchListIncrementally` from `js/nostr/client.js` into a new `RelayBatchFetcher` class in `js/nostr/relayBatchFetcher.js` to reduce complexity in `NostrClient`.
Moved `withRequestTimeout` to `js/utils/asyncUtils.js` to make it reusable and remove duplication.
Updated `js/nostr/client.js` to use these new components while preserving existing behavior and specific logging for COUNT diagnostics.
- Created `js/nostr/relayBatchFetcher.js`
- Updated `js/utils/asyncUtils.js`
- Refactored `js/nostr/client.js`
- Verified with existing tests
Co-authored-by: PR0M3TH3AN <[email protected]>