Refactor navigation icon

[tom2drum]

Description and Related Issue(s)

This pull request refactors navigation icons by removing redundant *_slim variants, consolidating icon usage, and organizing navigation-related assets under a dedicated icons/navigation directory for clearer semantics and reuse across the UI.

It updates various navigation, search, entity, rewards, and ZetaChain-related components to use the new icon set and type definitions without changing user-facing behavior beyond icon appearance.

Proposed Changes

• Move navigation-related icons into the icons/navigation directory and wire them into navigation/search components.
• Remove unused or redundant *_slim icon variants and consolidate references to the standard icon names.
• Update UI components (navigation, search results, entity tags, rewards, ZetaChain views, etc.) and public/icons/name.d.ts to reference the new icons and exports.

Breaking or Incompatible Changes

• Existing overrides or external consumers that rely on removed *_slim icon filenames or old icon locations may need to be updated to the new names and icons/navigation paths.

Additional Information

• Changes are limited to icons, typings, and components that render them; copy and core behavior remain unchanged.

Checklist for PR author

• I have tested these changes locally.
• I added tests to cover any new functionality, following this guide
• Whenever I fix a bug, I include a regression test to ensure that the bug does not reappear silently.
• If I have added, changed, renamed, or removed an environment variable
  • I updated the list of environment variables in the documentation
  • I made the necessary changes to the validator script according to the guide
  • I added "ENVs" label to this pull request