[website] first version of configurable plots (#32)

beat/web/experiments/static/experiments/js/utils.js

beat/web/navigation/admin.py

beat/web/navigation/api.py

beat/web/navigation/api_urls.py

beat/web/navigation/models.py

beat/web/navigation/templates/navigation/search.html

beat/web/navigation/utils.py

beat/web/navigation/views.py

beat/web/settings/settings.py

beat/web/ui/static/ui/js/beat.search.panels.js