Extract a `Frame` struct from `Window` (#3273)

This PR pulls the previous/current frame data out of the `Window` and
into a separate `Frame` struct.

Release Notes:

- N/A
5480c01cdaMax Brunsfeld committed on 11/8/2023, 6:47:11 PM· committed by GitHubparentscb03159ca2cc42
3 files changedLine totals unavailable