Update limit pushdown rule to support offsets

[andygrove]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.
PR #2521 adds support for OFFSET. The limit push down rule will not push the limit through offset so we should optimize this at some point.

Describe the solution you'd like
If we have offset 5 limit 10 then we should be able to push limit 15 (5 + 10) beneath the offset operator in some cases. There is probably a lot more to this though.

Describe alternatives you've considered
None

Additional context
None

[Ted-Jiang]

I will take this. ❤️