Switch service point filter from checkboxes to multi-select picker

Purpose: The multi-select picker provides a better (and safe) user interface for libraries with more than a handful of Service points. This is because service points are library-defined and, while most institutions won't have more than about 10, we really don't know how many they might add (especially if they are large or a consortium).

Scenarios:

1. Scenario:
   • Given the Pickup service point filter on Circ log
   • When displayed
   • Then it should be displayed as the multi-select menu instead of checkboxes (like the Tags filter above or the Effective location filter in Inventory)