accessibility: add SortAnnouncer for aria-live sorting updates across tables

[onyekachi66]

Closes #145

Description

This PR improves accessibility for screen-reader users by adding a reusable, visually-hidden SortAnnouncer component that utilizes an aria-live="polite" region. When a user changes the sorting order or cycles back to an unsorted state in the table headers, the live region automatically announces the changes (e.g., "Sorted by Amount, ascending" or "Sorting cleared").

Key Changes

1. New Component: Created SortAnnouncer.tsx to manage sorting state announcements using a useEffect hook that avoids triggering screen-reader announcements on initial mount.
2. Table Component Integration:
   • Wired the announcer into AnchorTable.tsx.
   • Wired the announcer into PoolTable.tsx.
   • Wired the announcer into SettlementTable.tsx.
3. Test Extensions:
   • Added live-region state assertions to AnchorTable.test.tsx.
   • Added live-region state assertions to PoolTable.test.tsx.
   • Added live-region state assertions to SettlementTable.test.tsx.
4. Test Fix:
   • Corrected a pre-existing failing test assertion in PoolTable.test.tsx where it was expecting "Pools search and refresh" instead of the actual "Pools search" role label, and updated its query scope to search for the sibling Refresh button globally rather than inside the search region.

Verification

All 27 targeted tests across AnchorTable.test.tsx, PoolTable.test.tsx, and SettlementTable.test.tsx pass successfully.

[Jagadeeshftw]

Closing — this branch's SortAnnouncer/aria-live accessibility work is already on main via #390. Merging main into this branch produces a zero-diff result, so there's nothing left to merge. Thanks for the contribution!