Add support for session windows

[doctorhulk]

Hello everyone,

Is there any pending idea to extend windowing functions in Trino and the window frame specification to support session windows? I think about something like has been recently added to Spark: https://www.databricks.com/blog/2021/10/12/native-support-of-session-window-in-spark-structured-streaming.html.

We're evaluating Trino for our use case, were we analyze user activity on a website, and that would be very helpful.

Regards,
Piotr