Search queries in daemon mode now run on a background thread via
DaemonHandle::query_async(). Results are posted back to the main
thread via glib::spawn_future_local + futures_channel::oneshot.
The GTK event loop is never blocked by IPC, eliminating perceived
input lag.
Local mode (dmenu) continues to use synchronous search since it
has no IPC overhead.
vikingowl
8f7501038d