Expose CopyExec metrics in Spark

[andygrove]

What is the problem the feature request solves?

In the native planner, we insert a CopyExec node into the plan. The timings from this operator are not visible in the Spark UI.

Describe the potential solution

I think there are two choices:

1. Create a JVM equivalent CopyExec and make this available in the plan in Spark
2. Have CopyExec include its time in its child operators metrics

Additional context

No response