Add basic breadcrumb on search result.

- Some line formatting
- Some UI tweak to make it more polished
- Updated the way we generate docid
- Use screen title as leaf level breadcrumb and display on UI (TBD how
  to get parent level titles)
- Hardcode breadcrumb for installed app results

Bug: 32936784
Test: make RunSettingsRoboTests
Change-Id: I18e0780f91b1123bbf25cd99adf2e2a5f684a83c