Add support for window function bindings (#521)

* Add support for window function bindings

* Refactor PyWindow to be moved to Expr submodule

* Adjust Expr module imports, moved WindowFrame to expr

* Update src/expr/window.rs

---------

Co-authored-by: Andy Grove <[email protected]>

Author: jdye64

Cargo.lock

@@ -33,7 +33,6 @@
     SessionConfig,
     RuntimeConfig,
     ScalarUDF,
-    WindowFrame,
 )
 
 from .common import (
@@ -86,6 +85,8 @@
     DropTable,
     Repartition,
     Partitioning,
+    Window,
+    WindowFrame,
 )
 
 __version__ = importlib_metadata.version(__name__)
@@ -99,6 +100,7 @@
     "Expr",
     "AggregateUDF",
     "ScalarUDF",
+    "Window",
     "WindowFrame",
     "column",
     "literal",