Add job run timing

[bgins]

General Description

Add job run timing on the solver and report deals and timings to the stats API.

Which system(s) or functionality does this affect

This pull request affects the solver and the stats API. It has an indirect impact on module authors and job creators who will use the data to establish job timeouts.

Describe the changes, and how this affects/ interacts with each system.

We start recording a job run time when the job offer is inserted into the solver database and end when the job creator finishes downloading the job outputs. We will only time successful jobs at first and will consider timing failed jobs in future work.