Get the previous history entry matching a substring query.
The query is captured on the first call of a navigation session
(when _current_index == -1) and reused for all subsequent calls until
reset_navigation. Passing a different value on later calls has
no effect.
Current input text. Saved only on the first call of a navigation session; ignored on subsequent calls.
Substring to match against history entries. Captured once on the first call of a navigation session.
