Add a way to delete/purge job repository artifacts

Section 11.2 States:

11.2 Job Repository Artifact Lifecycle
All job repository artifacts are created by the batch runtime during job processing and exist until deleted
by an implementation provided means.

There is currently no way to delete old job data. An API should be designed to purge the data. The API should support at least the following ways to purge.

• Purge by a date range
• Purge by before date
• Purge by number of jobs to keep
• Purge by job id