Report both execution time and wall clock time

[openjck]

There seems to be a discrepancy between the run time that ensemble-transposer reports and the run time that GCP reports.

For example, the following are the last two lines in the most recent GCP run. (The first line is generated by ensemble-transposer, but the second line is generated by GCP.)

Wrote all files in 4227.8s
Function execution took 3146 ms, finished with status: 'ok'

It could be that that one time is reported in execution time and another is reported in wall clock time.