Update search indexes for Dashboards and Panels to Ferret, plus various minor fixes
Depends on D20410. Ref T13272. Dashboards/Panels currently use older "ngram" indexing, which is a less-powerful precursor to Ferret. Throw away the ngram index and provide a Ferret index instead. Also:
- Remove the NUX state, which links to the wrong place now and doesn't seem terribly important.
- Add project tags to the search result list.
- Make the "No Tags" tag a little less conspicious.
- Indexed dashboards and panels.
- Searched for dashboards and panels via SearchEngine using Ferret "query" field.
- Searched for panels via "Add Existing Panel" datasource typeahead.
- Searched for dashboards via "Add Menu Item > Dashboard" on a ProfileMenu via typeahead.
- Viewed dashboard NUX state (no special state, but no more bad link to "/create/").
- Viewed dashboard list, saw project tags.
- Viewed dashboards with no project tags ("No Tags" is now displayed but less visible).
Reviewed By: amckinley
Maniphest Tasks: T13272
Differential Revision: https://secure.phabricator.com/D20411