Develop a plan for provenance tracking

The ESAP Vision tells us that ESAP should track provenance for its data products. It expands on that to say:

In general, it seems impossible for ESAP to provide full provenance information given the nature of its workflow. In particular, while ESAP can track the queries used to select an input dataset, it cannot track whatever IDA is performed by the user (which may include filtering or otherwise modifying the input data). Suggestion: the shopping basket should track the source of each entry (that is, what query was run to generate it, etc), and record what other services the data has been round-tripped through.

It's also been suggested that we look at the IVOA Provenance Model.

We should do that, and come up with a concrete proposal for what's required here.