Switch for enabling runner timestamps

What does this MR do?

We sometimes have long running jobs, and its difficult to know how long the individual steps take

This change adds a timestamp to the logger configuration eg

this can be enabled with the --log-timestamps switch or LOG_TIMESTAMPS=1

Why was this MR needed?

The JSON and Text loggers support time duration output, but the runner logger does not.

What's the best way to test this MR?

Added tests, need to run as full runner to see results.

What are the relevant issue numbers?