refactor(layouts): extract independent komorebi-layouts crate

This commit moves layout-related code into a new workspace crate
komorebi-layouts, with the intention of re-using it all in komorebi for
Mac instead of maintaining two separate implementations.

Cargo.toml

@@ -5,6 +5,7 @@ members = [
   "komorebi",
   "komorebi-client",
   "komorebi-gui",
+  "komorebi-layouts",
   "komorebic",
   "komorebic-no-console",
   "komorebi-bar",