[Bug]: Pressing `ctrl+f` a second time does not allow native search

Affects only `master`. This is a regression as this was fixed a long time ago already for the old design of unified search. ## Problem When pressing `ctrl + f` the unified search is focused and opened. Pressing `ctrl + f` again still prevents default behavior. ## Solution Pressing `ctrl + f` when unified search is already open should be ignored by unified search and the event *must not* be prevented, moreover the unified search should be closed to allow native browsers in-app-search (e.g. looking for some specific text).