fix(animation): add async focus manager for mff

This commit adds a new focus manager module to be used to trigger async
focus changes with mouse follows focus updates. Currently this should
only need to be used with animations as all other focus calls are
synchronous.

fix #910

komorebi/src/lib.rs

@@ -8,6 +8,7 @@ pub mod com;
 pub mod ring;
 pub mod colour;
 pub mod container;
+pub mod focus_manager;
 pub mod monitor;
 pub mod monitor_reconciliator;
 pub mod process_command;