[SPARK-46913][WIP] Add support for processing/event time based timers with transformWithState operator

[anishshri-db]

What changes were proposed in this pull request?

Add support for processing/event time based timers with transformWithState operator

Why are the changes needed?

Changes are required to add event-driven timer based support for stateful streaming applications based on state api v2

Does this PR introduce any user-facing change?

Yes

How was this patch tested?

Added unit tests

Was this patch authored or co-authored using generative AI tooling?

No