Enhanced search and navigation between matches

[parsapanahpoor]

• Issue Title: Enhance search with next/previous navigation and filters
• Description:
  Improve the existing search feature by allowing users to jump between matches (next/previous) and optionally filter by key, value, or data type.
• Tasks:
  • Add "Next" / "Previous" navigation for search results.
  • Optionally add filters: search in keys, values, or both.
  • Optionally add filter by data type (string, number, bool, etc.).
  • Make the current match clearly highlighted.
  • Ensure performance is acceptable for medium/large JSON.
  • Update docs and demos to show the new search UX.