Fix typo
Define `::selector` and search modes

`lt.plugins.aleph.browser/selector` is a filter-list extended with
GUI elements that allows the user to change internal parameters.

Currently, `selector` includes buttons to update the search key and
itemizing function (“search modes”).
Use Aleph selectors over plain filter-lists

The Behavior and Object selectors also benefit from search-modes:
- behaviors can now be searched either by name or triggers
- objects can now be searched either by type or id
Refresh selectors on first load