* Move filter code to the navigation package
- Moves filter-related code to navigation, so it can be shared between components and the app
- Fixes spelling of “flatten”
- Update README docs with new functions
* Use `get` to prevent errors if options is not an array/is empty
* Update documentation and tests
* Move nav-utils and history to new package
* Update config to build and use new navigation package
* Update all imports to use new navigation package
* Remove unnecessary README
* Update nav-utils path