Add timer logging to dumps

[dosumis]

For working on improving pipeline scaling, It would be very helpful to have timings for each goal in the dumps Makefile:

https://github.com/VirtualFlyBrain/vfb-pipeline-dumps/blob/master/dumps.Makefile

This could be achieved with simple shell commands echoed to a timing log file output.

[dosumis]

The process.sh records some timing (I think) but not so fine grained.