feat: enhance search bar with debounced autocomplete and term highlighting

[miss-yusrah]

closes #80

Description

Enhances the search experience by displaying relevant suggestions dynamically as users type into the notification search bar.

Changes Made

• Debounced User Input: Implemented a new useDebounce hook to optimize input handling and drastically reduce unnecessary search cycles.
• Asynchronous Suggestions: Introduced a SearchAutocomplete component that dynamically fetches event suggestions asynchronously (preventing UI blocking or freezing).
• Match Highlighting: Added a textual highlighting utility highlighting the exact substring or part of the search string that triggered the match dynamically in the respective suggestion result.
• Graceful Empty States: The suggestions dropdown gracefully handles fetching states and displays a "No suggestions found" message for queries returning no results.
• Integration: Replaced the legacy text <input> in EventFiltersBar.tsx with the completed autocomplete component safely tracking the global store queries.

Acceptance Criteria Covered

• ✅ Suggestions appear with minimal delay.
• ✅ Search requests are optimized (debounced input stream).
• ✅ Empty states display correctly.
• ✅ Matches highlight terms actively.

All tests, linting tools, and CI build scripts passed locally.