Add support for filtering the schedules table (#590)

* Add support for searching the schedules table at /schedules

* Move filtering logic into SchedulesTable

* Extract out a <Search> component

* Improve margins in Link Schedule dialog

* Add support for filtering in Link Schedule

* Add support for filtering by date

* rename param for clarity

* Remove unused imports

* Fix schedules with empty values always showing up in search results

* Fix matching behavior