Archive spec schemas don't work.

[mfeit-internet2]

@szymontrocha reported that he was unable to use the pScheduler archive spec's label feature in his pSConfig file:

"archives": {
        "pmp-central.geant.org": {
            "schema": 3,
            "archiver": "esmond",
            "label": "pmp-central-ma",
            "data": {
                "measurement-agent": "{% scheduled_by_address %}",
                "url": "https://pmp-central.geant.org/esmond/perfsonar/archive/"
            }
        }
    },

# psconfig validate pscfg-psmall.json
Loading template ...... OK
Validating JSON schema ...... FAIL

pSConfig JSON is not valid. Encountered the following validation errors:

   Node: /archives/pmp-central.geant.org
   Error: Properties not allowed: label, schema.

The best I can figure from a short dive into pSConfig is that it has its own validator for the archive spec and passed the data blob to pScheduler for validation. That's the correct thing to do, but pSConfig's validator has to keep up with pScheduler's.

Ergo:

• [ ] pSConfig's validator needs to be brought up to date (Short-term solution)
• [ ] pScheduler's API needs an endpoint for validating entire archive specs and pSConfig should use that (Long-term solution) See https://github.com/perfsonar/pscheduler/issues/1306.