Add support for window function bindings

[jdye64]

Which issue does this PR close?

Closes #520

[andygrove]

@jdye64 Is there any overlap between this PR and the recently merged PR that added Window Frame bindings?

#509

[jdye64]

I had missed that one. Yes, seems to be a lot of overlap. Let me rebase with main and remove the duplicate pieces.

[jdye64]

I think I'm going to move window_frame.rs into the expr directory since that lines up with arrow-datafusion location and also rename it to just window.rs and include both window and window_frame logic in the single file. Will post the commit here shortly.

[andygrove]

@dlovell fyi