Consider defining subject_intent

[marcvs]

The intent of a subject may be useful for some systems to identify what a certain authentication is supposed to be used for. Relying parties may use this for finer grained authorisation, as well as for optimisation of the service they provide.

Examples are:

• monitoring: Testing, must work, should not use lots of resources, might be low prio
• bulk: The default, e.g. if claim not present
• realtime: I was in projects that failed, because such a feature was not present
• demo: ...

Things to discuss:

• Do we need this at all?
• Do we want to support / suggest a controlled vocabulary for the values?
  • Alternative: provide the claim only.

[marcvs]

This goes well together with subject_type, which we already have. i.e. you could have a robot that is monitoring or bulk, you could have a user that is doing monitoring, bulk, or realtime