Move PhysicalExpr and PhysicalSortExpr to physical-expr-core

[jayzhan211]

          I see -- it seems like the issue is that the accumulator implementation requires PhysicalSortExpr.

To pull the code into its own crate maybe we could pull out the relevant pieces of datafusion-physical-expr into datafusion-physical-core or something (as a follow on PR)

Originally posted by @alamb in #9874 (comment)

We want to move aggregate function to aggreagate-functions crate but avoid importing whole physical-expr crate. Therefore, we need to move PhysicalSortExpr for ordering, and of course PhysicalExpr to physical-expr-core. Then, we can import it only.

part of #8708

[alamb]

FYI @mustafasrepo