Implement field data job logging

[ZavenArra]

Field data job logging is a generic way to keep track of jobs that were run on field data, and what version of the algorithm was used. This is helpful for reprocessing, and provides a standard way to check on the status of a given entity.

This will be implemented as an enhancement once #103 and #107 are completed. The field data job log will replace the *_processed_at fields in field data entities.

This ticket will be described in more detail. By way of example, job_type could be root_check_v1, root_check_v2, session_segmentation_v1, etc. The job details JSON can store the entity type, entity id, and any job parameters. This can be used for joins using postgres json/nosql query syntax for check for processing status on sessions, captures, etc.