Future improvements - multiple job query and job labeling

[vsoch]

I'd like the following to work:

• To be able to give an attribute to a job on submit (I know how to do this in Python and on the command line) but then be able to query (in Python) to check that a job of interest has that attribute defined for that value. This use case simplified is "check if the current job has attribute A == B.
• Taking this ability and applying to query across all jobs. This use case simplified is "Show me all the jobs with attribute A == B.

The first will allow to validate that a user owns a job, and the second will be to make the poll a little more efficient (one request to the server instead of the currently separate).

Pinging @grondo for wisdom next week!

[vsoch]

A better idea maybe! If we can have the flux restful api server authenticate the user, and then given a matched user on the system, sign the payload as that user: https://github.com/flux-framework/flux-core/blob/de55b0f83af6119b9f6770ef02591b77ac253b84/t/scripts/sign-as.py#L10 that should enforce permissions despite not being run by the user.

Thanks for the wisdom @garlick !