Avoid unpacking dictionaries for inputs to SortExec

[andygrove]

What is the problem the feature request solves?

We currently unpack dictionaries before SortExec, which seems inefficient. I experimented with removing this unpacking and was able to run TPC-H without error, but TPC-DS failed with an out of bounds error.

It is possible that we will need to make changes in upstream DataFusion to support this.

Describe the potential solution

No response

Additional context

No response